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塑料注塑模具中英文对照外文翻译文献

外文翻译及原文(文档含英文原文和中文翻译)【原文一】CONCURRENT DESIGN OF PLASTICS INJECTION MOULDS AbstractThe plastic product manufacturing industry has been growing rapidly in recent years. One of the most popular processes for making plastic parts is injection moulding. The design of injection mould is critically important to product quality and efficient product processing.Mould-making companies, who wish to maintain the competitive edge, desire to shorten both design and manufacturing leading times of the by applying a systematic mould design process. The mould industry is an important support industry during the product development process, serving as an important link between the product designer and manufacturer. Product development has changed from the traditional serial process of design, followed by manufacture, to a more organized concurrent process where design and manufacture are considered at a very early stage of design. The concept of concurrent engineering (CE) is no longer new and yet it is still applicable and relevant in today’s manuf acturing environment. Team working spirit, management involvement, total design process and integration of IT tools are still the essence of CE. The application of The CE process to the design of an injection process involves the simultaneous consideration of plastic part design, mould design and injection moulding machine selection, production scheduling and cost as early as possible in the design stage.This paper presents the basic structure of an injection mould design. The basis of this system arises from an analysis of the injection mould design process for mould design companies. This injection mould design system covers both the mould design process and mould knowledge management. Finally the principle of concurrent engineering process is outlined and then its principle is applied to the design of a plastic injection mould.Keywords :Plastic injection mould design, Concurrent engineering, Computer aided engineering, Moulding conditions, Plastic injection moulding, Flow simulation1.IntroductionInjection moulds are always expensive to make, unfortunately without a mould it can not be possible ho have a moulded product. Every mould maker has his/her own approach to design a mould and there are many different ways of designing and building a mould. Surely one of the most critical parameters to be considered in the design stage of the mould is the number of cavities, methods of injection, types of runners, methods of gating, methods of ejection, capacity and features of the injection moulding machines. Mould cost, mould quality and cost of mould product are inseparableIn today’s completive environment, computer aided mould filling simulation packages can accurately predict the fill patterns of any part. This allows for quick simulations of gate placements and helps finding the optimal location. Engineers can perform moulding trials on the computer before the part design is completed. Process engineers can systematically predict a design and process window, and can obtain information about the cumulative effect of the process variables that influence part performance, cost, and appearance.2.Injection MouldingInjection moulding is one of the most effective ways to bring out the best in plastics. It is universally used to make complex, finished parts, often in a single step, economically, precisely and with little waste. Mass production of plastic parts mostly utilizes moulds. The manufacturing process and involving moulds must be designed after passing through the appearance evaluation and the structure optimization of the product design. Designers face a hugenumber of options when they create injection-moulded components. Concurrent engineering requires an engineer to consider the manufacturing process of the designed product in the development phase. A good design of the product is unable to go to the market if its manufacturing process is impossible or too expensive. Integration of process simulation, rapid prototyping and manufacturing can reduce the risk associated with moving from CAD to CAM and further enhance the validity of the product development.3. Importance of Computer Aided Injection Mould DesignThe injection moulding design task can be highly complex. Computer Aided Engineering (CAE) analysis tools provide enormous advantages of enabling design engineers to consider virtually and part, mould and injection parameters without the real use of any manufacturing and time. The possibility of trying alternative designs or concepts on the computer screen gives the engineers the opportunity to eliminate potential problems before beginning the real production. Moreover, in virtual environment, designers can quickly and easily asses the sensitivity of specific moulding parameters on the quality and manufacturability of the final product. All theseCAE tools enable all these analysis to be completed in a meter of days or even hours, rather than weeks or months needed for the real experimental trial and error cycles. As CAE is used in the early design of part, mould and moulding parameters, the cost savings are substantial not only because of best functioning part and time savings but also the shortens the time needed to launch the product to the market.The need to meet set tolerances of plastic part ties in to all aspects of the moulding process, including part size and shape, resin chemical structure, the fillers used, mould cavity layout, gating, mould cooling and the release mechanisms used. Given this complexity, designers often use computer design tools, such as finite element analysis (FEA) and mould filling analysis (MFA), to reduce development time and cost. FEA determines strain, stress and deflection in a part by dividing the structure into small elements where these parameters can be well defined. MFA evaluates gate position and size to optimize resin flow. It also defines placement of weld lines, areas of excessive stress, and how wall and rib thickness affect flow. Other finite element design tools include mould cooling analysis for temperature distribution, and cycle time and shrinkage analysis for dimensional control and prediction of frozen stress and warpage.The CAE analysis of compression moulded parts is shown in Figure 1. The analysis cycle starts with the creation of a CAD model and a finite element mesh of the mould cavity. After the injection conditions are specified, mould filling, fiber orientation, curing and thermal history, shrinkage and warpage can be simulated. The material properties calculated by the simulation can be used to model the structural behaviour of the part. If required, part design, gate location and processing conditions can be modified in the computer until an acceptable part is obtained. After the analysis is finished an optimized part can be produced with reduced weldline (known also knitline), optimized strength, controlled temperatures and curing, minimized shrinkage and warpage.Machining of the moulds was formerly done manually, with a toolmaker checking each cut. This process became more automated with the growth and widespread use of computer numerically controlled or CNC machining centres. Setup time has also been significantly reduced through the use of special software capable of generating cutter paths directly from a CAD data file. Spindle speeds as high as 100,000 rpm provide further advances in high speed machining. Cutting materials have demonstrated phenomenal performance without the use of any cutting/coolant fluid whatsoever. As a result, the process of machining complex cores and cavities has been accelerated. It is good news that the time it takes to generate a mould is constantly being reduced. The bad news, on the other hand, is that even with all these advances, designing and manufacturing of the mould can still take a long time and can be extremely expensive.Figure 1 CAE analysis of injection moulded partsMany company executives now realize how vital it is to deploy new products to market rapidly. New products are the key to corporate prosperity. They drive corporate revenues, market shares, bottom lines and share prices. A company able to launch good quality products with reasonable prices ahead of their competition not only realizes 100% of the market before rival products arrive but also tends to maintain a dominant position for a few years even after competitive products have finally been announced (Smith, 1991). For most products, these two advantages are dramatic. Rapid product development is now a key aspect of competitive success. Figure 2 shows that only 3–7% of the product mix from the average industrial or electronics company is less than 5 years old. For companies in the top quartile, the number increases to 15–25%. For world-class firms, it is 60–80% (Thompson, 1996). The best companies continuously develop new products. AtHewlett-Packard, over 80% of the profits result from products less than 2 years old! (Neel, 1997)Figure 2. Importance of new product (Jacobs, 2000)With the advances in computer technology and artificial intelligence, efforts have been directed to reduce the cost and lead time in the design and manufacture of an injection mould. Injection mould design has been the main area of interest since it is a complex process involving several sub-designs related to various components of the mould, each requiring expert knowledge and experience. Lee et. al. (1997) proposed a systematic methodology and knowledge base for injection mould design in a concurrent engineering environment.4.Concurrent Engineering in Mould DesignConcurrent Engineering (CE) is a systematic approach to integrated product development process. It represents team values of co-operation, trust and sharing in such a manner that decision making is by consensus, involving all per spectives in parallel, from the very beginning of the productlife-cycle (Evans, 1998). Essentially, CE provides a collaborative, co-operative, collective and simultaneous engineering working environment. A concurrent engineering approach is based on five key elements:1. process2. multidisciplinary team3. integrated design model4. facility5. software infrastructureFigure 3 Methodologies in plastic injection mould design, a) Serial engineering b) Concurrent engineeringIn the plastics and mould industry, CE is very important due to the high cost tooling and long lead times. Typically, CE is utilized by manufacturing prototype tooling early in the design phase to analyze and adjust the design. Production tooling is manufactured as the final step. The manufacturing process and involving moulds must be designed after passing through the appearance evaluation and the structure optimization of the product design. CE requires an engineer to consider the manufacturing process of the designed product in the development phase.A good design of the product is unable to go to the market if its manufacturing process is impossible. Integration of process simulation and rapid prototyping and manufacturing can reduce the risk associated with moving from CAD to CAM and further enhance the validity of the product development.For years, designers have been restricted in what they can produce as they generally have todesign for manufacture (DFM) – that is, adjust their design intent to enable the component (or assembly) to be manufactured using a particular process or processes. In addition, if a mould is used to produce an item, there are therefore automatically inherent restrictions to the design imposed at the very beginning. Taking injection moulding as an example, in order to process a component successfully, at a minimum, the following design elements need to be taken into account:1. . geometry;. draft angles,. Non re-entrants shapes,. near constant wall thickness,. complexity,. split line location, and. surface finish,2. material choice;3. rationalisation of components (reducing assemblies);4. cost.In injection moulding, the manufacture of the mould to produce the injection-moulded components is usually the longest part of the product development process. When utilising rapid modelling, the CAD takes the longer time and therefore becomes the bottleneck.The process design and injection moulding of plastics involves rather complicated and time consuming activities including part design, mould design, injection moulding machine selection, production scheduling, tooling and cost estimation. Traditionally all these activities are done by part designers and mould making personnel in a sequential manner after completing injection moulded plastic part design. Obviously these sequential stages could lead to long product development time. However with the implementation of concurrent engineering process in the all parameters effecting product design, mould design, machine selection, production scheduling,tooling and processing cost are considered as early as possible in the design of the plastic part. When used effectively, CAE methods provide enormous cost and time savings for the part design and manufacturing. These tools allow engineers to virtually test how the part will be processed and how it performs during its normal operating life. The material supplier, designer, moulder and manufacturer should apply these tools concurrently early in the design stage of the plastic parts in order to exploit the cost benefit of CAE. CAE makes it possible to replace traditional, sequential decision-making procedures with a concurrent design process, in which all parties can interact and share information, Figure 3. For plastic injection moulding, CAE and related design data provide an integrated environment that facilitates concurrent engineering for the design and manufacture of the part and mould, as well as material selection and simulation of optimal process control parameters.Qualitative expense comparison associated with the part design changes is shown in Figure 4 , showing the fact that when design changes are done at an early stages on the computer screen, the cost associated with is an order of 10.000 times lower than that if the part is in production. These modifications in plastic parts could arise fr om mould modifications, such as gate location, thickness changes, production delays, quality costs, machine setup times, or design change in plastic parts.Figure 4 Cost of design changes during part product development cycle (Rios et.al, 2001)At the early design stage, part designers and moulders have to finalise part design based on their experiences with similar parts. However as the parts become more complex, it gets rather difficult to predict processing and part performance without the use of CAE tools. Thus for even relatively complex parts, the use of CAE tools to prevent the late and expensive design changesand problems that can arise during and after injection. For the successful implementation of concurrent engineering, there must be buy-in from everyone involved.5.Case StudyFigure 5 shows the initial CAD design of plastics part used for the sprinkler irrigation hydrant leg. One of the essential features of the part is that the part has to remain flat after injection; any warping during the injection causes operating problems.Another important feature the plastic part has to have is a high bending stiffness. A number of feeders in different orientation were added to the part as shown in Figure 5b. These feeders should be designed in a way that it has to contribute the weight of the part as minimum aspossible.Before the design of the mould, the flow analysis of the plastic part was carried out with Moldflow software to enable the selection of the best gate location Figure 6a. The figure indicates that the best point for the gate location is the middle feeder at the centre of the part. As the distortion and warpage of the part after injection was vital from the functionality point of view and it has to be kept at a minimum level, the same software was also utilised to yiled the warpage analysis. Figure 5 b shows the results implying the fact that the warpage well after injection remains within the predefined dimensional tolerances.6. ConclusionsIn the plastic injection moulding, the CAD model of the plastic part obtained from commercial 3D programs could be used for the part performance and injection process analyses. With the aid ofCEA technology and the use of concurrent engineering methodology, not only the injection mould can be designed and manufactured in a very short of period of time with a minimised cost but also all potential problems which may arise from part design, mould design and processing parameters could be eliminated at the very beginning of the mould design. These two tools help part designers and mould makers to develop a good product with a better delivery and faster tooling with less time and money.References1. Smith P, Reinertsen D, The time-to-market race, In: Developing Products in Half the Time. New York, Van Nostrand Reinhold, pp. 3–13, 19912.Thompson J, The total product development organization. Proceedings of the SecondAsia–Pacific Rapid Product Development Conference, Brisbane, 19963.Neel R, Don’t stop after the prototype, Seventh International Conference on Rapid Prototyping, San Francisco, 19974.Jacobs PF, “Chapter 3: Rapid Product Development” in Rapid Tooling: Technologies and Industrial Applications , Ed. Peter D. Hilton; Paul F. Jacobs, Marcel Decker, 20005.Lee R-S, Chen, Y-M, and Lee, C-Z, “Development of a concurrent mould design system: a knowledge based approach”, Computer Integrated Manufacturing Systems, 10(4), 287-307, 19976.Evans B., “Simultaneous Engineering”, Mechanical Engi neering , V ol.110, No.2, pp.38-39, 19987.Rios A, Gramann, PJ and Davis B, “Computer Aided Engineering in Compression Molding”, Composites Fabricators Association Annual Conference , Tampa Bay, 2001【译文一】塑料注塑模具并行设计塑料制品制造业近年迅速成长。

塑料模具中英文对照外文翻译文献

中英文资料翻译The development of plastic mouldChina's industrial plastic moulds from the start to now, after more than half a century, there has been great development, mold levels have been greatly enhanced. Mould has been at large can produce 48-inch big-screen color TV Molded Case injection mold, 6.5 kg capacity washing machine full of plastic molds, as well as the overall car bumpers and dashboards, and other plastic mould precision plastic molds, the camera is capable of producing plastic mould , multi-cavity mold small modulus gear and molding mold. --Such as Tianjin and Yantai days Electrical Co., Ltd Polaris IK Co. manufactured multi-cavity mold VCD and DVD gear, the gear production of such size precision plastic parts, coaxial, beating requirements have reached a similar foreign the level of product, but also the application of the latest gear design software to correct contraction as a result of the molding profile error to the standard involute requirements. Production can only 0.08 mm thickness of a two-cavity mold and the air Cup difficulty of plastic doors and windows out of high modulus, and so on. Model cavity injection molding manufacturing accuracy of 0.02 to 0.05 mm, surface roughness Ra0.2 μ m, mold quality, and significantly increase life expectancy, non-hardening steel mould life up to 10~ 30 million, hardening steel form up to 50 ~ 10 million times, shorten the delivery time than before, but still higher than abroad, and the gap between a specific data table.Process, the multi-material plastic molding die, efficient multicolor injection mould, inserts exchange structure and core pulling Stripping the innovative design has also made great progress. Gas-assisted injection molding, the use of more mature technologies, such as Qingdao Hisense Co., Ltd., Tianjin factory communications and broadcasting companies, such as mold manufacturers succeeded in 29 ~ 34-inch TV thick-walled shell, as well as some parts on the use of gas-assisted mould technology Some manufacturers also use the C-MOLD gas-assisted software and achieved better results. Prescott, such as Shanghai, such as the new company will provide users with gas-assisted molding equipment and technology. Began promoting hot runner mold, and some plants use rate of more than 20 percent, the general heat-thermal hot runner, or device, a small number of units with the world's advanced level of rigorous hot runner-needle device, a small number of units with World advanced level of rigorous needle-hot runner mould. However, the use of hot runner overall rate of less than 10%, with overseas compared to 50 ~ 80%, the gap larger.In the manufacturing technology, CAD / CAM / CAE technology on the level of application of a new level to the enterprise for the production of household appliances representatives have introduced a considerable number of CAD / CAMsystems, such as the United States EDS UG Ⅱ, the United States Parametric Technology Pro / Engineer, the United States CV CADS5 company, the British company DOCT5 Deltacam, HZS's CRADE Japan, the company's Cimatron Israel, the United States AC-C-Tech Mold Company and Australia's MPA Mold flow Mold analysis software, and so on. These systems and the introduction of the software, althougha lot of money spent, but in our country die industry, and achievinga CAD / CAM integration, and to support CAE technology to forming processes such as molding and cooling, such as computer simulation, and achieved certain The technical and economic benefits, promote and facilitate China's CAD / CAM technology. In recent years, China's own development of the plastic mould CAD / CAM system has achieved significant development, the main guarantor Software Engineering Institute, is the development of CAXA, Huazhong University of Science HSC5.0 development of the system and injection mold CAE software, and so on, these Die of domestic software with the specific circumstances in the application of computer and lower prices, and other characteristics, in order to further universal CAD / CAM technology has created good conditions.In recent years, China has been more extensive use of some new plastic mold steel, such as: P20, 3Cr2Mo, PMS, SM Ⅰ, SM Ⅱ, and the quality of life of mold has a direct significant impact on the overall use of the still less . Plastic Moulds standard model planes, such as standard putter and spring has given more applications, and there have been some of the commercializationof domestic hot runner system components. However, at present China Die level of standardization and commercialization in the general level of below 30 percent and foreign advanced industrial countries has reached 70 percent compared to 80 percent, still a large gap. Table 1, at home and abroad plastic mould technology comparison table? Domestic projects abroad cavity injection model mm0.02 accuracy of 0.005 ~0.01 ~0.05mm cavity surface roughness Ra0.01 ~ 0.05 μ mRa0.20 μ m non-hardened steel die life 10 to 60 million 10 ~ 30 million hardened steel die life 160 ~ 300 million of 50 ~ 100 million hot runner mould overall utilization rate of more than 80 per cent less than 10 per cent level of standardization of 70 ~80% less than 30% of medium-sized plastic mould production cycle about a month 2 ~4 months in the mold industry in the amount of 30 to 40% 25 to 30% According to the parties concerned forecast, the market's overall vigorous mold is a smooth upward, in the next Die market, the development of plastic mould faster than the other Die, die in the proportion of industry will gradually improve. With the continuous development of the plastics industry, put on the plastic mold growing demands is a normal, and so sophisticated, large-scale, complex, long-life plastic mould development will be higher than the overall pace of development. At the same time, imports in recent years because of the mold, precision, large, complex, long-life die in the majority, therefore, reduce imports, increase Guochanhualu: perspective, in the mold of such high-end market share will gradually increase. The rapid development of theconstruction industry so that the various Profile Extrusion Die, PVC plastic pipe fittings Die Die market become a new economic growth point, the rapid development of highways, car tires also put a higher demand, radial tire Die, Die particularly active pace of development will also be higher than the overall average level of the plastic and wood, plastic and metal to make plastic molds in the automotive, motorcycle industry in the demand for huge household appliances industry in the "10th Five-Year Plan" period have greater development, especially refrigerators,air-conditioners and microwave ovens, and other parts of the great demand for plastic moulds, and electronics and communications products, in addition to audio-video products, such as color televisions, laptop computers and set-top boxes will be given a wider network development, which are Plastic Mold market is the growth point. Second, China's industrial and technological plastic mould the future direction of the major developments will include: 1, raising large, sophisticated, complex, long-life mold design and manufacturing standards and proportion. This is due to the molding plastic mould products increasingly large, complex and high-precision requirements, as well as requirements for high productivity and the development of a multi-mode due. 2, in the design and manufacture of plastic mould fully promote the use of CAD / CAM / CAE technology. CAD / CAM technology has developed into a relatively mature technology common in recent years CAD / CAM technology hardware and software prices has been reduced to SMEsgenerally acceptable level of popularity for further create good conditions; based on network CAD / CAM / CAE system integration structure the initial signs of emerging, and it will solve the traditional mixed CAD / CAM system can not meet the actual production process requirements of the division of collaboration; CAD / CAM software will gradually improve intelligence plastic parts and the 3-D mold design and prototyping process 3-D analysis will be in our plastic mould industries play an increasingly important role. 3, promote the use of hot runner technology, gas-assisted injection molding technology and high-pressure injection molding technology. Using hot runner mould technology can improve the productivity and quality of parts and plastic parts can be substantial savings of raw materials and energy conservation, extensive application of this technology is a big plastic mould changes. Hot Runner components formulate national standards, and actively produce cheap high-quality components, the development of hot runner mold is the key. Gas-assisted injection molding product quality can be guaranteed under the premise of substantially lower cost. Currently in the automotive and appliance industries gradually promote the use of the Chiang Kai-shek. Gas-assisted injection molding of the ordinary than the traditional injection of more parameters need to identify and control, and its more commonly used in large, complex products, mold design and control more difficult, therefore, the development of gas-assisted molding flow analysis software It seems veryimportant. On the other hand in order to ensure precision plastic parts to continue to study the development of technology and high-pressure injection molding and injection-compression molding mould and die technology is also very important. 4, the development of new plastics molding technology and rapid economic mold. To adapt to more variety, less volume of production. 5, and improve standardization of plastic mould standard parts usage. China's mold and die level of standard parts standardization still low, the gap between the large and foreign, to a certain extent constraining the development of industries in our country die, die to improve quality and reduce manufacturing costs Die, Die standard parts to vigorously promote the application. To this end, first of all, to formulate a unified national standards, and in strict accordance with the standards of production, secondly it is necessary to gradually scale production, to improve the commercialization of the standard of quality, and reduce costs;again it is necessary to further increase the standard specifications of varieties. 6, Die application quality materials and advanced surface treatment technology for improving the quality of life and mold it is necessary. 7, research and application of high-speed die measurement technology and reverse engineering. CMM-use 3D scanner or reverse engineering is the realization of plastic moulds CAD / CAM one of the key technologies.Research and Application of diversity, adjustment, cheap detection equipment is to achieve the necessary precondition forreverse engineering.塑料模具的发展我国塑料模工业从起步到现在，历经半个多世纪，有了很大发展，模具水平有了较大提高。

注塑模部分中英文对照

注塑模部分中英文对照塑料成形模具mould for plastics热塑性塑料模mould for thermoplastics热固性塑料模mould for thermosets压缩模compression mould压注模、传递模transfer mould注射模injection mould热塑性塑料注射模injection mould for thermoplastics热固性塑料注射模injection mould for thermoses成形零件定模stationary mould fixed half动模movable mould moving half定模座板fixed clamp plate, top clamping plate. top plate动模座板moving clamp plate. bottom clamping plate. bottom plate 上模座板upper clamping plate下模座板lower clamping plate凹模固定板cavity-retainer plate型芯固定板core-retainer plate凸模固定板punch-retainer plate模套chase. bolster. frame支承板backing plate. supprr plate垫块spacer parallel支架ejector housing. mould base leg动模movable mould moving half定模座板fixed clamp plate, top clamping plate. top plate动模座板moving clamp plate. bottom clamping plate. bottom plate 上模座板upper clamping plate下模座板lower clamping plate凹模固定板cavity-retainer plate型芯固定板core-retainer plate凸模固定板punch-retainer plate模套chase. bolster. frame垫块spacer parallel支架ejector housing. mould base leg压力铸造模具die-casting die压铸模零部件定模fixed die, cover die定模座板fixed clamping plate定模套板bolstor, fixed die动模moving die,ejector die动模座板moving clamping plate 直流道sprue横流道runner内浇口gate。

注塑模具设计外文翻译

毕业设计（论文）外文资料翻译及原文（2012届）题目电话机三维造型与注塑模具设计指导教师院系工学院班级学号姓名二〇一一年十二月六日【译文一】塑料注塑模具并行设计Assist.Prof.Dr. A. Y AYLA /Prof.Dr. Paş a YAYLA摘要塑料制品制造业近年迅速成长。

其中最受欢迎的制作过程是注塑塑料零件。

注塑模具的设计对产品质量和效率的产品加工非常重要。

模具公司想保持竞争优势,就必须缩短模具设计和制造的周期。

模具是工业的一个重要支持行业，在产品开发过程中作为一个重要产品设计师和制造商之间的联系。

产品开发经历了从传统的串行开发设计制造到有组织的并行设计和制造过程中,被认为是在非常早期的阶段的设计。

并行工程的概念(CE)不再是新的,但它仍然是适用于当今的相关环境。

团队合作精神、管理参与、总体设计过程和整合IT工具仍然是并行工程的本质。

CE过程的应用设计的注射过程包括同时考虑塑件设计、模具设计和注塑成型机的选择、生产调度和成本中尽快设计阶段。

介绍了注射模具的基本结构设计。

在该系统的基础上,模具设计公司分析注塑模具设计过程。

该注射模设计系统包括模具设计过程及模具知识管理。

最后的原则概述了塑料注射模并行工程过程并对其原理应用到设计。

关键词:塑料注射模设计、并行工程、计算机辅助工程、成型条件、塑料注塑、流动模拟1、简介注塑模具总是昂贵的,不幸的是没有模具就不可能生产模具制品。

每一个模具制造商都有他/她自己的方法来设计模具,有许多不同的设计与建造模具。

当然最关键的参数之一,要考虑到模具设计阶段是大量的计算、注射的方法,浇注的的方法、研究注射成型机容量和特点。

模具的成本、模具的质量和制件质量是分不开的在针对今天的计算机辅助充型模拟软件包能准确地预测任何部分充填模式环境中。

这允许快速模拟实习,帮助找到模具的最佳位置。

工程师可以在电脑上执行成型试验前完成零件设计。

工程师可以预测过程系统设计和加工窗口,并能获得信息累积所带来的影响,如部分过程变量影响性能、成本、外观等。

模具设计外文翻译--注射／压缩流体组合模塑的数值模拟

附录二：外文翻译原件及翻译稿Numerical simulation of injection/compression liquid composite moldingPart 1. Mesh generationK.M. Pillai a, C.L. Tucker III, F.R a. Phelan Jr ba Department of Mechanical and Industrial Engineering, University of Illinois,1206 W. Green Street, Urbana, IL61801, USAb Polymer Composites Group, Polymers Division, Building 224, Room B108, National Institute ofStandards and Technology, Gaithersburg, MD20899, USAAccepted 14 June 1999───────────────────────────────────────AbstractThis paper presents a numerical simulation of injection/compression liquid composite molding, where the fiber preform is compressed to a desired degree after an initial charge of resin has been injected into the mold. Due to the possibility of an initial gap at the top of the preform and out-of-plane heterogeneity in the multi-layered fiber preform, a full three-dimensional (3D) flow simulation is essential. We propose an algorithm to generate a suitable 3D finite element mesh, starting from a two-dimensional shell mesh representing the geometry of the mold cavity. Since different layers of the preform have different compressibility, and since properties such as permeability are a strong function of the degree of compression, a simultaneous prediction of preform compression along with the resin flow is necessary for accurate mold filling simulation. The algorithm creates a coarser mechanical mesh to simulate compression of the preform, and a finer flow mesh to simulate the motion of the resin in the preform and gap. Lines connected to the top and bottom plates of the mold, called spines, are used as conduits for the nodes. A method to generate a surface parallel to a given surface, thereby maintaining the thickness of the intermediate space, is used to construct the layers of the preform in the mechanical mesh. The mechanical mesh is further subdivided along the spines to create the flow mesh. Examples of the three-dimensional meshes generated by the algorithm are presented. 1999 Elsevier Science Ltd. All rights reserved.Keywords: Liquid composite molding (LCM); E. Resin transfer molding (RTM)───────────────────────────────────────1. IntroductionLiquid composite molding (LCM) is emerging as an important technology to make net-shape parts of polymer-matrix composites. In any LCM process, a preform of reinforcing fibers is placed in a closed mold, then a liquid polymer resin is injected into the mold to infiltrate the preform. When the mold is full, the polymer is cured by a crosslinking reaction to become a rigid solid. Then the mold is opened to remove the part. LCM processes offer a way to produce high-performance composite parts using a rapid process with low labor requirement.This paper deals with a particular type of LCM process called injection/compression liquid composite molding (I/C-LCM). In I/C-LCM, unlike other types of LCM processes, the mold is only partially closed when resin injection begins. This increases the cross-sectional area availablefor the resin flow, and decreases flow resistance by providing high porosity in the reinforcement. Often, the presence of a gap at the top of the preform further facilitates the flow. After all of the resin has been injected, the mold is slowly closed to its final height, causing additional resin flow and saturating all portions of the preform. The I/CLCM process fills the mold more rapidly, and at a lower pressure than the other LCM processes that use injection alone.Complete filling of the mold with adequate wetting of the fibers is the primary objective of any LCM mold designer; incomplete filling in the mold leads to production of defective parts with dry spots. There are many factors which affect the filling of the mold: permeability of the preform, presence of gaps in the mold to facilitate resin flow, arrangement of inlet and outlet gates, injection rates of resin from different inlet ports, etc. Often it is not possible for the mold designer to visualize and design an adequate system for resin infusion by intuition alone, and mold filling simulations are used to optimize mold performance. The situation in I/C-LCM is more complex than ordinary LCM because of compression of the mold during the filling operation. As a result, numerical simulation of the mold filling process in I/C-LCM becomes all the more important.I/C-LCM fiber preforms frequently comprise layers of different reinforcing materials such as biaxial woven fabrics, stitch-bonded uniaxial fibers, random fibers. Each type of material has a unique behavior as it is compressed in the mold. When such different materials are layered to form the preform, each of them will compress by different amounts as the mold is closed. This behavior is illustrated in Fig. 1, which shows a small piece of a mold. Here the lighter center layer deforms much more than the darker outer layer as the mold is closed.(B) After compression (A) Before compressionFig. 1. Uneven deformation of preform layers under compression.Capturing this deformation behavior during compression is critical to the accuracy of any I/C-LCM process model. Resin flows through the preform at all stages of compression, and the porosity and permeability of the preform are critical in determining the resin flow. The ratio of deformed volume to initial volume determines the porosity of each preform layer, and from this one can determine the layer's permeability, either from a theoretical prediction or a correlation of experimental data. Because of this strong coupling between the state of compression in a preform layer and its permeability, computations for fluid flow and preform compression have to be done simultaneously for mold filling simulations in I/C-LCM.Significant steps have already been taken to computationally model the mold filling in the I/C-LCM process. A computer program called crimson, is capable of isothermal mold fillingsimulation which involves simultaneous fluid flow and preform compression computations in the flow domain. But the initial capacity of crimson is limited to two-dimensional (2D) planar geometries where prediction of preform compression is straightforward. Deformation of the preform is modeled using the incremental linearized theory of elasticity; the mathematics simplifies due to reduction in the number of degrees of freedom (DOF) associated with displacement from the usual three to one along the thickness direction. However parts made by the I/C-LCM process typically have complicated three-dimensional shapes and this reduction of the mathematical complexity is no longer possible. The present paper describes our effort to expand the capability of crimson by enabling it to tackle any arbitrary non-planar three dimensional (3D) mold geometry.Most injection molding simulation programs read for the mold geometry in the form of a shell mesh. Even if it were possible to transmit the full geometrical information about the mold through a 3D mesh, it still is difficult to incorporate all the information of relevance to the process engineer. The latter needs to know the thicknesses of various layers of fiber mats and their corresponding porosities at each time step. As a result, it is very important that elements representing different layers of preform in the 3D finite element mesh fall within separate layered regions. Overlap of an element onto more than one region is not acceptable as the element has to carry the material properties, such as porosity, permeability, of only one fiber mat. Mesh-generators in state-of-the-art commercial software such as PATRAN are not designed to generate such a 3D mesh. Consequently, we decided to create a preprocessor suitable for I/C-LCM mold filling simulation.The objectives of this paper are to introduce basic ideas about modeling mold filling in 3D I/C-LCM parts, and to introduce an algorithm to generate a 3D finite element mesh from a given 2D shell mesh for preform and flow computations. In subsequent papers, we will model finite deformation of preform using the non-linear theory of elasticity, and use this information to model resin flow in an I/C-LCM mold.2. Generating a 3D mesh from the given 2D shell meshOur aim is to develop a preprocessor that can generate 3D finite element meshes for flow computations starting from a 2D shell mesh. We wish to allow the I/C-LCM process engineer to include all relevant information such as thicknesses of the layers of the preform, thickness of the gap, into the mesh.A - open gap everywhere C - just touching / partly compressedD - fully compressed everywhere B - open gap / just touchingFig. 2. A schematic describing the various stages of the compression/injection molding process. The top plate of the mold moves along theclamping vector, while the bottom plate is stationary. Stages A–C arethree possible starting positions of the top plate. Stage D shows the finalconfiguration of the mold when it is fully compressed.Fig.2 describes the three possible starting mold configurations (A-C) for a typical angular part geometry. Case A represents the starting configuration for the open mold injection/compression (I/C) molding, with ample gap between the top plate and preform. Cases B and C occur when the gap is partly or completely eliminated before the start of the injection process. In the former, the preform is completely uncompressed with gaps at a few places. In the latter, the gap is removed at the cost of partial compression of the preform in certain regions. In the present paper, mesh generation for configuration A only will be addressed. Once this mesh is created, cases B and C can be generated by solving for the mechanical compression of the preform.As we shall see in the subsequent papers, six-noded wedge elements and eight-noded brick elements are adequate for modeling both the resin flow and preform compression. Our mesh generation algorithm is designed to generate such elements from the three- and four-noded triangular and quadrilateral elements of the shell mesh.2.1. Mechanical and flow meshesDevelopment of the 3D mesh for flow computations from a given 2D shell mesh, representing the part geometry, is divided into two stages. In the first stage, an intermediate mechanical mesh is created, where the number of layers of elements equals the number of fiber mats in the lay-up, with the thickness of the mats equal to the height of those elements. Such a coarse mesh is adequate to track deformation of the mats during compression of the mold. In the second stage, the mechanical mesh is further subdivided along the thickness direction to create a more refined mesh, called the flow mesh, which is used for flow calculations.3. Basic concepts of mesh generation algorithmWe first introduce two basic ideas that form the backbone of our mesh generation algorithm: spines and parallel surfaces.3.1. Use of spinesOne of the salient features of our mesh generation technique is the use of spines to track the nodes of the 3D mechanical mesh. This is similar to the use of spines in the free boundary problems where they have been used to adapt the computational mesh with time. These spines are lines connecting node points of the top mold surface to their counterparts of the bottom mold surface.4. AlgorithmThe main actions carried out in our mesh generation algorithm are as follows:1. Read data describing the 2D shell mesh. The mesh data is read, along with the information important for process modeling such as direction of clamping, properties of fiber mats, initial gap provided at the top of the preform.2. Construct the upper surface of the final part. The upper surface is generated parallel to the input 2D shell mesh which represents the bottom, immovable surface of the mold. The inputthicknesses between the given and upper surfaces are taken to be the final thickness of the I/C-LCM mold (equal to the desired part thickness).5. Examples and discussionA computer program has been developed to implement the mesh generation algorithm, and tested for its efficacy and robustness. In the following sections, examples of the creation of 3D computational meshes from 2D shell meshes are presented. Since the thicknesses in the I/C-LCM parts are much smaller than their other dimensions, realistic meshes are relatively thin. To highlight important features of the algorithm, the thicknesses of the meshes are scaled up in the following examples. In each example, a gap that is a certain fraction of the total thickness of the uncompressed preform is provided between the upper surface of the preform and the top mold plate.6. Summary and conclusionsIn this paper, we present a methodology to create 3D finite element meshes for modeling mold filling in I/CLCM. We propose the concept of predicting preform compression using the coarse mechanical mesh, and predicting fluid flow using the finer flow mesh. A mesh-generating algorithm, to create the mechanical and flow meshes from a given shell mesh, is presented. This algorithm incorporates information about the position of fiber mat interfaces in a multi-layered preform, which is crucial for accurate modeling of the filling process. A technique to create surfaces parallel to any arbitrary shell mesh surface enables us to represent the interfaces accurately. Further, the use of spines in mesh generation reduces the number of unknowns at each node from three to one. The algorithm is used successfully to create the mechanical and flow meshes from two different shell meshes; its robustness is demonstrated by creating a 3D mesh from a shell mesh for an arbitrary mold shape. The need to refine the shell mesh in the region of a step change in the thickness of the mold is the main limitation of the algorithm. In subsequent papers, we will use the mechanical and flow meshes to simulate preform compression and resin flow during mold filling in I/C-LCM.注射／压缩流体组合模塑的数值模拟第一部分网格生成K.M. Pillai a, C.L. Tucker III, F.R a. Phelan Jr ba伊利诺斯大学机械工业工程系1206 W. Green Street, Urbana, IL61801, USAb国家标准与技术研究所，聚合物部，聚合物合成组Building 224, Room B108,Gaithersburg, MD 20899,USA收稿日期：1999年6月14日───────────────────────────────────────摘要文章介绍了注入模型中的树脂在一次初填充后其纤维预型件被压缩到所需的程度时，注射／压缩流体组合模塑的一种数值模拟。

模具塑料注射成型外文翻译外文文献英文文献

模具塑料注射成型外文翻译外文文献英文文献XXXThere are many different processing methods used to convert plastic pellets。

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模具外文翻译外文文献英文文献注塑模

模具外文翻译外文文献英文文献注塑模The Injection Molding1、The injection moldingInjection molding is principally used for the production of the thermoplastic parts,although some progress has been made in developing a method for injection molding some thermosetting materials.The problem of injection a method plastic into a mold cavity from a reservoir of melted material has been extremely difficult to solve for thermosetting plastic which cure and harden under such conditions within a few minutes.The principle of injection molding is quite similar to that of die-casting.The process consists of feeding a plastic compound in powered or granular form from a hopper through metering and melting stages and then injecting it into a mold.After a brief cooling period,the mold is opened and the solidified part ejected.Injection-molding machine operation.The advantage of injection molding are：（ⅰ）a high molding speed adapter for mass production is possible；（ⅱ）there is a wide choice of thermoplastic materials providing a variety of useful properties；（ⅲ）it is possible to mold threads,undercuts,side holes,and large thin section.2、The injection-molding machineSeveral methods are used to force or inject the melted plastic into the mold.The most commonly used system in the larger machines is the in-line reciprocating screw,as shown in Figure 2-1.The screw acts as a combination injection and plasticizing unit.As the plastic is fed to the rotating screw,it passes through three zones as shown：feed,compression,and metering.After the feed zone,the screw-flight depth is gradually reduced,force theplastic to compress.The work is converted to heat by conduction from the barrel surface.As the chamber in front of the screw becomes filled,it forces the screw back,tripping a limit switch that activates a hydraulic cylinder that forces the screw forward and injects the fluid plastic into the closed mold.An antiflowback valve presents plastic under pressure from escaping back into the screw flight.The clamping force that a machine is capable of exerting is part of the size designation and is measured in tons.A rule-of-thumb can be used to determine the tonnage required for a particular job.It is based on two tons of clamp force per square inch of projected area.If the flow pattern is difficult and the parts are thin,this may have to go to three or four tons.Many reciprocating-screw machines are capable of handing thermosetting plastic materials.Previously these materials were handled by compression or transfer molding.Thermosetting materials cure or polymerize in the mold and are ejected hot in the range of 375°C～410°C.T hermosetting parts must be allowed to cool in the mold in order or remove them without distortion. Thus thermosetting cycles can be faster.Of course the mold must be heated rather than chilled,as with thermoplastics.3、Basic Underfeed MouldA simple mould of this type is shown in Figure3-1,and the description of the design and the opening sequence follows.The mould consists of three basic parts,namely：the moving half,the floating cavity plate and the feed plate respectively.The moving half consists of The moving mould plate assembly,support block,backing plate,ejector assembly and the pin ejection system.Thus the moving half in this design is identical with the moving half of basic moulds.The floating cavity plate,which may be of the integer or insert-bolster design,is located on substantial guide pillars（not shown）fitted in the feed plate.These guide pillars must be of sufficient length to support the floating cavity plate over its full movement and still project to perform the function of alignment between the cavity and core when the mould is being closed.Guide bushes are fitted into the moving mould plate and the floating cavity plate respectively.The maximum movement of the floating cavity plate is controlled by stop or similar device.The moving mould plate is suitably bored to provide a clearance for the stop bolt assembly.The stop bolts must be long enough to provide sufficient space between the feed plate and the floating cavity plate for easy removal of the feed system.The minimum space provide for should be 65mm just sufficient for an operator to remove the feed system by hand if necessary.The desire operating sequence is for the first daylight to occur between the floating cavity plate.This ensures the sprue is pulled from the sprue bush immediately the mouldis opened.T o achieve this sequence,springs may be incorporated between the feed plate and the floating cavity plate.The springs should be strong enough to give an initial impetus to the floating cavity plate to ensure it moves away with the moving half.It is normal practice to mount the springs on the guide pillars（Figure3-2）and accommodate them in suitable pocket in the cavity plate.The major part of the feed system（runner and sprue）is accommodated in the feed plate to facilitate automatic operation,the runner should be of a trapezoidal form so that once it is pulled from the feed plate is can easily beextracted.Note that if a round runner is used,half the runner is formed in the floating cavity plate,where it would remain,and be prevented from falling or being wiped clear when the mould is opened.Now that we have considered the mould assembly in the some detail,we look at the cycle of operation for this type of mould.The impressions are filled via the feed system（Figure3-1（a））and after a suitable dwell period,the machine platens commence to open.A force is immediately exerted by the compression springs,which cause the floating cavity plate to move away with the moving half as previously discussed.The sprue is pulled from the sprue bush by the sprue puller.After the floating cavity plate has moved a predetermined distance,it is arrested by the stop bolts.The moving half continues to move back and the moldings,having shrunk on to the cores,are withdrawn from the cavities.The pin gate breaks at its junction with the runner（Figure3-1（b））.The sprue puller,being attached to the moving half,is pulled through the floating cavity plate and thereby release the feed system which is then free to fall between the floating cavity plate and the feed plate.The moving half continues to move back until the ejector system is operated and the moldings are ejected （Figure3-1（c））.When the mould is closed,the respective plates are returned to their molding position and the cycle is repeated.4、Feed SystemIt is necessary to provide a flow-way in the injection mould to connect the nozzle（of the injection machine）to each impression.This flow-way is termed the feed system.Normally thefeed system comprises a sprue,runner and gate.These terms applyequally to the flow-way itself,and to the molded material which is remove from the flow-way itself in the process of extracted the molding.A typical feed system for a four-impression,two plate-type mould is shown in Figure4-1.It is seen that the material passes through the sprue,main runner,branch runner and gate before entering the impression.As the temperature of molten plastic is lowered which going through the sprue and runner,the viscosity will rise;however,the viscosity is lowered by shear heat generated when going through the gate to fill the cavity.It is desirable to keep the distance that the material has to travel down to a minimum to reduce pressure and heat losses.It is for this reason that careful consideration must be given to the impression layout gate’s design.4.1.SprueA sprue is a channel through which to transfer molten plastic injected from the nozzle of the injector into the mold.It is a part of sprue bush,which is a separate part from the mold.4.2.RunnerA runner is a channel that guides molten plastic into the cavity of a mold.4.3.GateA gate is an entrance through which molten plastic enters the cavity.The gate has the following function：restricts the flow and the direction of molten plastic；simplifies cutting of a runner and moldings to simplify finishing of parts；quickly cools and solidifies to avoid backflow after molten plastic has filled up in the cavity.4.4.Cold slug wellThe purpose of the cold slug well,shown opposite the sprue,is theoretically to receive the material that has chilled at the front of nozzle during the cooling and ejection phase.Perhaps of greater importance is the fact that it provides position means whereby the sprue bush for ejection purposes.The sprue,the runner and the gate will be discarded after a part is complete.However,the runner and the gate are important items that affect the quality or the cost of parts.5、EjectionA molding is formed in mould by injecting a plastic melt,under pressure,into animpression via a feed system.It must therefore be removed manually.Furthermore,all thermoplastic materials contract as they solidify,which means that the molding will shrink on to the core which forms it.This shrinkage makes the molding difficult to remove. Facilities are provided on the injection machine for automatic actuation of an ejector system,and this is situated behind the moving platen.Because of this,the mould’s ejector system will be most effectively operated if placed in the moving half of the mould,i.e. the half attached to the moving platen.We have stated previously that we need to eject the molding from the core and it therefore follows that the core,too,will most satisfactorily be located in the moving half.The ejector system in a mould will be discussed under three headings,namely：（ⅰ）the ejector grid;（ⅱ）the ejector plate assembly; and（ⅲ）the method of ejection.5.1、Ejector gridThe ejector grid（Figure5-1）is that part of the mould which supports the mould plate and provides a space into which theejector plate assembly can be fitted and operated.The grid normally consists of a back plate on to which is mounted a number of conveniently shaped “support blocks”.The ejector plate assembly is that part of the mould to which the ejector element is attached.The assembly is contained in a pocket,formed by the ejector grid,directly behind the mould plate.The assembly（Figure5-2）consists of an ejector plate,a retaining plate and an ejector rod.One end of this latter member is threaded and it is screwed into the ejector plate.In this particular design the ejector rod function not only as an actuating member but also as a method of guiding the assembly.Note that the parallel portion of the ejector rod passes through an ejector rod bush fitted in the back plate of the mould.5.2、Ejection techniquesWhen a molding cools,it contracts by an amount depending on the material being processed.For a molding which has no internal form,for example,a solid rectangular block,the molding will shrink away from the cavity walls,thereby permitting a simple ejection technique to be adopted.However,when the molding has internal form,the molding,as it cools,will shrink onto the core and some positive type of ejection is necessary.The designer has several ejection techniques from which to choose，but in general,the choice will be restricted depending upon the shape of the molding.The basic ejection techniques are as follows：（ⅰ）pin ejection（ⅱ）sleeve ejection（ⅲ）stripper plate ejection and（Ⅳ）air ejection.Figure 2-1aFigure 2-1bFigure 3-1Figure 3-2Figure 4-1aFigure 4-1bFigure 5-1Figure 5-2注塑模1、注塑模尽管成型某些热固性材料的方法取得了一定的进步，但注塑模主要（还是）用来生产热塑性塑件。

注塑模具设计与制造外文文献翻译

2 Injection molding machineFrom Plastics Wiki, free encyclopediaInjection molding machines consist of two basic parts, an injection unit and a clamping unit. Injection molding machines differ in both injection unit and clamping unit. The name of the injection molding machine is generally based on the type of injection unit used.2.1Types of injection molding machinesMachines are classified primarily by the type of driving systems they use: hydraulic, electric, or hybrid.2.1.1HydraulicHydraulic presses have historically been the only option available to molders until Nissei Plastic Industrial Co., LTD introduced the first all-electric injection molding machine in 1983. The electric press, also known as Electric Machine Technology (EMT), reduces operation costs by cutting energy consumption and also addresses some of the environmental concerns surrounding the hydraulic press.2.1.2ElectricElectric presses have been shown to be quieter, faster, and have a higher accuracy, however the machines are more expensive.2.1.3HybridHybrid injection molding machines take advantage of the best features of both hydraulic and electric systems. Hydraulic machines are the predominant type in most of the world, with the exception of Japan.2.2Injection unitThe injection unit melts the polymer resin and injects the polymer melt into the mold. The unit may be: ram fed or screw fed.The ram fed injection molding machine uses a hydraulically operated plunger to push the plastic through a heated region. The high viscosity melt is then spread into a thin layer by a "torpedo" to allow for better contact with the heated surfaces. The melt converges at a nozzle and is injected into the mold.Reciprocating screw A combination melting, softening, and injection unit in an injection molding machine. Another term for the injection screw. Reciprocating screws are capable of turning as they move back and forth.The reciprocating screw is used to compress, melt, and convey the material. The reciprocating screw consists of three zones (illustrated below):•feeding zone•compressing zone•metering zoneWhile the outside diameter of the screw remains constant, the depth of the flights on the reciprocating screw decreases from the feed zone to the beginning of the metering zone. These flights compress the material against the inside diameter of the barrel, which creates viscous (shear) heat. This shear heat is mainly responsible for melting the material. The heater bands outside the barrel help maintain the material in the molten state. Typically, a molding machine can have three or more heater bands or zones with different temperature settings.Injection molding reciprocating screw An extruder-type screw rotates within a cylinder, which is typically driven by a hydraulic drive mechanism. Plastic material is moved through the heated cylinder via the screw flights and the material becomes fluid. The injection nozzle is blocked by the previous shot, and this action causes the screw to pump itself backward through the cylinder. (During this step, material is plasticated and accumulated for the next shot.) When the mold clamp has locked, the injection phase takes place. At this time, the screw advances, acting as a ram. Simultaneously, the non-return valve closes off the escape passages in the screw and the screw serves as a solid plunger, moving the plastic ahead into the mold. When the injection stroke and holding cycle is completed, the screw is energized to return and the non-return valve opens, allowing plastic to flow forward from the cylinder again, thus repeating the cycle.2.2.1Feed hopperThe container holding a supply molding material to be fed to the screw. The hopper located over the barrel and the feed throat connects them.2.2.2Injection ramThe ram or screw that applies pressure on the molten plastic material to force it into the mold cavities.2.2.3Injection screwThe reciprocating-screw machine is the most common. This design uses the same barrel for melting and injection of plastic.The alternative unit involves the use of separate barrels for plasticizing and injecting the polymer. This type is called a screw-preplasticizer machine or two-stage machine. Plastic pellets are fed from a hopper into the first stage, which uses a screw to drive the polymer forward and melt it. This barrel feeds a second barrel, which uses a plunger to inject the melt into the mold. Older machines used one plunger-driven barrel to melt and inject the plastic. These machines are referred to as plunger-type injection molding machines.2.2.4BarrelBarrel is a major part that melts resins transmitted from hopper through screws and structured in a way that can heat up resins to the proper temperature. A band heater, which can control temper atures in five sections, is attached outside the barrel. Melted resins are supplied to the mold passing through barrel head, shot-off nozzle, and one-touch nozzle.2.2.5Injection cylinderHydraulic motor located inside bearing box, which is connected to injection cylinder load, rotates screw, and the melted resins are measures at the nose of screw. There are many types of injection cylinders that supply necessary power to inject resins according to the characteristics of resins and product types at appropriate speed and pressure. This model employs the double cylinder type. Injection cylinder is composed of cylinder body, piston, and piston load.2.3Clamping unitThe clamping unit holds the mold together, opens and closes it automatically, and ejects the finished part. The mechanism may be of several designs, either mechanical, hydraulic or hydromechanical.Toggle clamps - a type clamping unit include various designs. An actuator moves the crosshead forward, extending the toggle links to push the moving platen toward a closed position. At the beginning of the movement, mechanical advantage is low and speed is high; but near the end of the stroke, the reverse is true. Thus, toggle clamps provide both high speed and high force at different points in the cycle when they are desirable. They are actuated either by hydraulic cylinders or ball screws driven by electric motors. Toggle-clamp units seem most suited to relatively low-tonnage machines.Two clamping designs: (a) one possible toggle clamp design (1) open and (2) closed; and (b) hydraulic clamping (1) open and (2) closed. Tie rods used to guide movuing platens not shown.Hydraulic clamps are used on higher-tonnage injection molding machines, typically in the range 1300 to 8900 kN (150 to 1000 tons). These units are also more flexible than toggle clamps in terms of setting the tonnage at given positions during the stroke.Hydraulic Clamping System is using the direct hydraulic clamp of which the tolerance is still and below 1 %, of course, better than the toggle system. In addition, the Low Pressure Protection Device is higher than the toggle system for 10 times so that the protection for the precision and expensive mold is very good. The clamping force is focus on the central for evenly distribution that can make the adjustment of the mold flatness in automatically. Hydromechanical clamps -clamping units are designed for large tonnages, usually above 8900 kN (1000 tons); they operate by (1) using hydraulic cylinders to rapidly move the mold toward closing position, (2) locking the position by mechanical means, and (3) using high pressure hydraulic cylinders to finally close the mold and build tonnage.2.3.1Injection moldThere are two main types of injection molds: cold runner (two plate and three plate designs) and hot runner– the more common of the runnerless molds.2.3.2Injection platensSteel plates on a molding machine to which the mold is attached. Generally, two platens are used; one being stationary and the other moveable, actuated hydraulically to open and close the mold. It actually provide place to mount the mould. It contains threaded holes on which mould can be mounted using clamps.2.3.3Clamping cylinderA device that actuates the chuck through the aid of pneumatic or hydraulic energy.2.3.4Tie BarTie bars support clamping power, and 4 tie bars are located between the fixing platen and the support platen.3 Injection mouldFrom Wikipedia, the free encyclopediaMold A hollow form or cavity into which molten plastic is forced to give the shape of the required component. The term generally refers to the whole assembly of parts that make up the section of the molding equipment in which the parts are formed. Also called a tool or die. Moulds separate into at least two halves (called the core and the cavity) to permit the part to be extracted; in general the shape of a part must be such that it will not be locked into the mould. For example, sides of objects typically cannot be parallel with the direction of draw (the direction in which the core and cavity separate from each other). They are angled slightly; examination of most household objects made from plastic will show this aspect of design, known as draft. Parts that are "bucket-like" tend to shrink onto the core while cooling and, after the cavity is pulled away, are typically ejected using pins. Parts can be easily welded together after moulding to allow for a hollow part (like a water jug or doll's head) that couldn't physically be designed as one mould.More complex parts are formed using more complex moulds, which may require moveable sections, called slides, which are inserted into the mould to form particular features that cannot be formed using only a core and a cavity, but are then withdrawn to allow the part to be released. Some moulds even allow previously moulded parts to be re-inserted to allow a new plastic layer to form around the first part. This system can allow for production of fully tyred wheels.Traditionally, moulds have been very expensive to manufacture; therefore, they were usually only used in mass production where thousands of parts are being produced.Molds require: Engineering and design, special materials, machinery and highly skilled personnel to manufacture, assemble and test them.Cold-runner moldCold-runner mold Developed to provide for injection of thermoset material either directly into the cavity or through a small sub-runner and gate into the cavity. It may be compared to the hot-runner molds with the exception that the manifold section is cooled rather than heated to maintain softened but uncured material. The cavity and core plates are electrically heated to normal molding temperature and insulated from the cooler manifold section.3.1.1Types of Cold Runner MoldsThere are two major types of cold runner molds: two plate and three plate.3.1.2Two plate moldA two plate cold runner mold is the simplest type of mold. It is called a two plate mold because there is one parting plane, and the mold splits into two halves. The runner system must be located on this parting plane; thus the part can only be gated on its perimeter.3.1.3Three plate moldA three plate mold differs from a two plate in that it has two parting planes, and the mold splits into three sections every time the part is ejected. Since the mold has two parting planes, the runner system can be located on one, and the part on the other. Three plate molds are used because of their flexibility in gating location. A part can be gated virtually anywhere along its surface.3.1.4AdvantagesThe mold design is very simple, and much cheaper than a hot runner system. The mold requires less maintenance and less skill to set up and operate. Color changes are also very easy, since all of the plastic in the mold is ejected with each cycle.3.1.5DisadvantagesThe obvious disadvantage of this system is the waste plastic generated. The runners are either disposed of, or reground and reprocessed with the original material. This adds a step in the manufacturing process. Also, regrind will increase variation in the injection molding process, and could decrease the plastic's mechanical properties.3.1.6Hot runner moldHot-runner mold -injection mold in which the runners are kept hot and insulated from the chilled cavities. Plastic freezeoff occurs at gate of cavity; runners are in a separate plate so they are not, as is the case usually, ejected with the piece.Hot runner molds are two plate molds with a heated runner system inside one half of the mold.A hot runner system is divided into two parts: the manifold and the drops. The manifold has channels that convey the plastic on a single plane, parallel to the parting line, to a point abovethe cavity. The drops, situated perpendicular to the manifold, convey the plastic from the manifold to the part.3.1.7Types of Hot Runner MoldsThere are many variations of hot runner systems. Generally, hot runner systems are designated by how the plastic is heated. There are internally and externally heated drops and manifolds.3.1.8Externally heated hot runnersExternally heated hot runner channels have the lowest pressure drop of any runner system (because there is no heater obstructing flow and all the plastic is molten), and they are better for color changes none of the plastic in the runner system freezes. There are no places for material to hang up and degrade, so externally heated systems are good for thermally sensitive materials.3.1.9Internally heated hot runnersInternally heated runner systems require higher molding pressures, and color changes are very difficult. There are many places for material to hang up and degrade, so thermally sensitive materials should not be used. Internally heated drops offer better gate tip control. Internally heated systems also better separate runner heat from the mold because an insulating frozen layer is formed against the steel wall on the inside of the flow channels.3.1.10 insulated hot runnersA special type of hot runner system is an insulated runner. An insulated runner is not heated; the runner channels are extremely thick and stay molten during constant cycling. This system is very inexpensive, and offers the flexible gating advantages of other hot runners and the elimination of gates without the added cost of the manifold and drops of a heated hot runner system. Color changes are very easy. Unfortunately, these runner systems offer no control, and only commodity plastics like PP and PE can be used. If the mold stops cycling for some reason, the runner system will freeze and the mold has to be split to remove it. Insulated runners are usually used to make low tolerance parts like cups and frisbees.3.1.11 DisadvantagesHot-runner mold is much more expensive than a cold runner, it requires costly maintenance, and requires more skill to operate. Color changes with hot runner molds can be difficult, since it is virtually impossible to remove all of the plastic from an internal runner system.3.1.12 AdvantagesThey can completely eliminate runner scrap, so there are no runners to sort from the parts, and no runners to throw away or regrind and remix into the original material. Hot runners are popular in high production parts, especially with a lot of cavities.Advantages Hot Runner System Over a Cold Runner System include:•no runners to disconnect from the molded parts•no runners to remove or regrind, thus no need for process/ robotics to remove them•having no runners reduces the possibility of contamination•lower injection pressures•lower clamping pressure•consistent heat at processing temperature within the cavity•cooling time is actually shorter (as there is no need for thicker, longer-cycle runners)•shot size is reduced by runner weight•cleaner molding process (no regrinding necessary)•nozzle freeze and sprue sticking issues eliminated中文翻译注塑模具设计与制造2 注射机选自《维基百科》注射机由两个基本部分组成，注射装置和夹紧装置。

塑料模具外文文献翻译、塑料制品的CADCAE集成的注塑模具设计系统外文翻译、中英文翻译

A CAD/CAE-integrated injection mold design system for plastic productsAbstract Mold design is a knowledge-intensive process. This paper describes a knowledge-based oriented, parametric, modular and feature-based integrated computer-aided design/computer-aided engineering (CAD/CAE) system for mold design. Development of CAx systems for numerical simulation of plastic injection molding and mold design has opened new possibilities of product analysis during the mold design. The proposed system integrates Pro/ENGINEER system with the specially developed module for the calculation of injection molding parameters, mold design, and selection of mold elements. The system interface uses parametric and CAD/CAE feature-based database to streamline the process of design, editing, and reviewing. Also presented are general structure and part of output results from the proposed CAD/ CAE-integrated injection mold design system.Keywords Mold design . Numerical simulation . CAD . CAE1 IntroductionInjection molding process is the most common molding process for making plastic parts. Generally, plastic injection molding design includes plastic product design, mold design, and injection molding process design, all of which contribute to the quality of the molded product as well as production efficiency [1]. This is process involving many design parameters that need to be considered in a concurrent manner. Mold design for plastic injection molding aided by computers has been focused by a number of authors worldwide for a long period. Various authors have developed program systems which help engineers to design part, mold, and selection parameters of injection molding. During the last decade, many authors have developed computer-aided design/computer-aided engineering (CAD/CAE) mold design systems for plastic injection molding. Jong et al. [2] developed a collaborative integrated design system for concurrent mold design within the CAD mold base on the web, using Pro/E. Low et al. [3] developed an application for standardization of initial design of plastic injection molds. The system enables choice and management of mold base of standard mold plates, but does not provide mold and injection molding calculations. The authors proposed a methodology of standardizing the cavity layout design system for plastic injection mold such that only standard cavity layouts are used. When standard layouts are used, their layout configurations can be easilystored in a database. Lin at al. [4, 5] describe a structural design system for 3D drawing mold based on functional features using a minimum set of initial information. In addition, it is also applicable to assign the functional features flexibly before accomplishing the design of a solid model for the main parts of a drawing mold. This design system includes modules for selection and calculation of mold components. It uses Pro/E modules Pro/Program and Pro/Toolkit, and consists of modules for mold selection, modification and design. Deng et al. [6, 7] analyzed development of the CAD/CAE integration. The authors also analyzed systems and problems of integration between CAD and CAE systems for numerical simulation of injection molding and mold design. Authors propose a feature ontology consisting of a number of CAD/CAE features. This feature represents not only the geometric information of plastic part, but also the design intent is oriented towards analysis. Part features contain the overall product information of a plastic part, wall features, development features (such as chamfer, ribs, boss, hole, etc.), treatment features which contain analysis-related design information and sub wall developed features. Wall and development features are so called ―component features‖. God ec et al. [8, 9] developed a CAE system for mold design and injection molding parameters calculations. The system is based on morphology matrix and decision diagrams. The system is used for thermal, rheological and mechanical calculation, and material base management,Fig. 1 General structure of integrated injection mold design system for plastic productsbut no integration with commercial CAx software is provided. Huang et al. [10] developed a mold-base design system for injection molding. The database they used was parametric and feature-based oriented. The system used Pro/E for modeling database components. Kong et al. [11]developed a parametric 3D plastic injection mold design system integrated with solid works. Other knowledge-based systems, such as IMOLD, ESMOLD, IKMOULD, and IKBMOULD, have been developed for injection mold design. IMOLD divides mold design into four major steps; parting surface design, impression design, runner system design, and mold-base design. The software uses a knowledge-based CAD system to provide an interactive environment, assist designers in the rapid completion of mold design, and promote the standardization of the mold design process. IKB-MOULD application consists of databases and knowledge bases for mold manufacturing. Lou et al. [12] developed an integrated knowledge-based system for mold base design. The system has module for impression calculation, dimension calculation, calculation of the number of mold plates and selection of injection machine. The system uses Pro/ Mold Base library. This paper describes KBS and key technologies, such as product modeling, the frame-rule method, CBS, and the neural networks. A multilayer neural network has been trained by back propagation BP. This neural network adopts length, width, height and the number of parts in the mold as input and nine parameters (length, width, and height of up and down set-in, mold bases side thickness, bottom thickness of the core, and cavity plates) as output. Mok et al. [13, 14] developed an intelligent collaborative KBS for injection molds. Mok at el. [15] has developed an effective reuse and retrieval system that can register modeled standard parts using a simple graphical user interface even though designers may not know the rules of registration for a database. The mold design system was developed using an Open API and commercial CAD/computer aided manufacturing (CAM)/CAE solution. The system was applied to standardize mold bases and mold parts in Hyundai Heavy Industry. This system adopted the method of design editing, which implements the master model using features. The developed system provides methods whereby designers can register the master model, which is defined as a function of 3D CAD, as standard parts and effectively reuse standard parts even though they do not recognize the rules of the database.Todic et al. [16] developed a software solution for automated process planning for manufacturing of plastic injection molds. This CAD/CAPP/CAM system does not provide CAE calculation of parameters of injection molding and mold design. Maican et al. [17] used CAE for mechanical, thermal, and rheological calculations. They analyzed physical, mechanical, and thermal properties of plastic materials. They defined the critical parameters of loaded part. Nardinet al. [18] tried to develop the system which would suit all the needs of the injection molding for selection of the part–mold–technology system. The simulation results consist of geometrical and manufacturing data. On the basis of the simulation results, part designers can optimize part geometry, while mold designers can optimize the running and the cooling system of the mold. The authors developed a program which helps the programmers of the injection molding machine to transfer simulation data directly to the machine. Zhou et al. [1] developed a virtual injection molding system based on numerical simulation. Ma et al. [19] developed standard component library for plastic injection mold design using an object-oriented approach. This is an objector iented, library model for defining mechanical components parametrically. They developed an object-oriented mold component library model for incorporating different geometric topologies and non-geometric information. Over the years, many researchers have attempted to automate a wholeFig. 2 Structure of module for numerical simulation of injection molding processFig. 3 Forms to define the mold geometrymold design process using various knowledge-based engineering (KBE) approaches, such as rule-based reasoning (RBR), and case base (CBR) and parametric design template (PDT). Chan at al. [20] developed a 3D CAD knowledge-based assisted injection mold design system (IKB mold). In their research, design rules and expert knowledge of mold design were obtained from experienced mold designers and handbooks through various traditional knowledge acquisition processes. The traditional KBE approaches, such as RBR, CBR, and simple PDT have been successfully applied to mold cavity and runner layout design automation of the one product mold. Ye et al. [21] proposed a feature-based and object-oriented hierarchical representation and simplified symbolic geometry approach for automation mold assembly modeling. The previously mentioned analysis of various systems shows that authors used different ways to solve the problems of mold design by reducing it to mold configureator (selector). They used CAD/CAE integration for creating precision rules for mold-base selection. Many authors used CAE system for numerical simulation of injection molding to define parameters of injection molding. Several also developed original CAE modules for mold and injection molding process calculation. However, common to all previously mentioned systems is the lack of module for calculation of mold and injection molding parameters which would allow integration with the results of numerical simulation. This leads to conclusion that there is a need to create a software system which integrates parameters of injection molding with the result obtained by numericalFig. 4 Forms to determine the distance between the cooling channels and mold cavityFig. 5 Mold-base selector formssimulation of injection molding, mold calculation, and selection. All this would be integrated into CAD/CAE-integrated injection mold design system for plastic products.2 Structure of integrated CAD/CAE systemAs is well known, various computational approaches for supporting mold design systems of various authors use design automation techniques such as KBE (RBR, CBR, PDT) or design optimisation techniques such as traditional (NLP,LP, BB, GBA, IR, HR) or meta heuristic search such as (TS, SA, GA) and other special techniques such as (SPA, AR, ED).The developed interactive software system makes possible to perform: 3D modeling of the parts, analysis of part design and simulation model design, numerical simulation of injection molding, and mold design with required calculations.The system consists of four basic modules:& Module for CAD modeling of the part& Module for numerical simulation of injection molding processFig. 6 Form for mechanical mold calculation& Module for calculation of parameters of injection molding and mold design calculation and selection& Module for mold modeling (core and cavity design and design all residual mold components) The general structure of integrated injection mold design system for plastic products is shown in Fig. 1.2.1 Module for CAD modeling of the part (module I)The module for CAD modeling of the part is the first module within the integrated CAD/CAE system. This module is used for generating CAD model of the plastic product and appropriate simulation model. The result of this module is solid model of plastic part with all necessary geometrical and precision specifications. Precision specifications are: project name, number, feature ID, feature name, position of base point, code number of simulation annealing, trade material name, material grade, part tolerance, machine specification (name, clamping force, maximal pressure, dimensions of work piece), and number of cavity. If geometrical and precision specification is specified (given) with product model, the same are used as input to the nextmodule, while this module is used only to generate the simulation model.2.2 Module for numerical simulation of injection molding process (module II)Module II is used for numerical simulation of injection molding process. User implements an iterative simulation process for determining the mold ability parameters of injection molding and simulation model specification. The structure of this module is shown in Fig. 2.After a product model is imported and a polymer is selected from the plastic material database, user selects the best location for gating subsystem. The database contains rheological, thermal, and mechanical properties of plastic materials. User defines parameters of injection molding and picks the location for the gating subsystem. Further analyses are carried out: the plastic flow, fill time, injection pressure, pressure drop, flow front temperature, presence of weld line, presence of air traps, cooling quality, etc.The module offers four different types of mold flow analysis. Each analysis is aimed at solving specific problems:& Part analysis—This analysis is used to test a known gate location, material, and part geometry to verify that a part will have acceptable processing conditions.& Gate analysis—This analysis tests multiple gate locations and compares the analysis outputs to determine the optimal gate location.& Sink mark analysis—This analysis detects sink mark locations and depths to resolve cosmetic problems before the mold is built eliminating quality disputes that could arise between the molder and the customer.The most important parameters are the following: [22]& Part thickness& Flow length& Radius and drafts,& Thickness transitions& Part material& Location of gates& Number of gates& Mold temperature& Melt temperature& Injection pressure& Maximal injection molding machine pressureIn addition to the previously mentioned parameters of injection molding, the module shows following simulation results: welding line position, distribution of air traps, the distribution of injection molding pressure, shear stressFig. 7 Segment of the mechanical calculation algorithmdistribution, temperature distribution on the surface of the simulation model, the quality of filling of a simulation model, the quality of a simulation model from the standpoint of cooling, and time of injection molding [22, 23]. A part of output results from this module are the input data for thenext module. These output results are: material grade and material supplier, modulus of elasticity in the flow direction, modulus of elasticity transverse direction, injection pressure, ejection temperature, mold temperature, melting temperature, highest melting temperature thermoplastic, thermoplastic density in liquid and solid state, and maximum pressure of injection molding machine. During implementation of iterative SA procedure, user defines the moldability simulation model and the parameters of injection molding. All results are represented by different colors in the regions of the simulation model.2.3 Module for calculation of parameters of injection molding and mold design calculation and selection (module III)This module is used for analytical calculations, mold sizing, and its selection. Two of the more forms for determining the dimensions of core and cavity mold plates are shown in Fig. 3.Based on the dimensions of the simulation model and clamping force (Fig. 3) user selects the mold material and system calculates the width and length of core and cavity plates. Wall thickness between the mold cavity to the cooling channel can be calculated with the following three criteria: criterion allowable shear stress, allowable bending stress criterion, and the criterion of allowable angle isotherms are shown in Fig. 4 [22, 24]. The system adopts the maximum value of comparing the values of wall thickness calculated by previously mentioned criteria.Fig. 8 Forms for standard mold plates selectionFig. 9 Forms for mold plate model generationBased on the geometry of the simulation model, user select shape and mold type. Forms for the selection mold shape, type, and subsystems are shown in Fig. 5. Once these steps are completed, user implements the thermal, rheological, and mechanical calculation of mold specifications. An example of one of the several forms for mechanical mold calculation is shown in Fig. 6.Segment of the algorithm of mechanical calculations is shown in Fig. 7.f max maximal flexure of cavity platef dop allowed displacement of cavity plateε elastic deformationαmin minimal value of shrinkage factorE k modulus of elasticity of cavity plateG shear modulusS k wall thickness distance measuring between cavity and waterlined KT cooling channel diameterAfter the thermal, rheological, and mechanical calculations, user selects mold plates from the mold base. Form for the selection of standard mold plates is shown in Fig. 8. The system calculates the value of thickness of risers, fixed, and movable mold plates (Fig. 8). Based on the calculated dimensions, the system automatically adopts the first major standard value for the thickness of risers, movable, and fixed mold plate. Calculation of the thickness and the adoption of standard values are presented in the form as shown in Fig. 8.The interactive system recommends the required mold plates. The module loads dimensions from the database and generates a solid model of the plate. After the plate selection, the plate is automatically dimensioned, material plate isFig. 10 Structure of module IVassigned, and 3D model and 2D technical drawing are generated on demand. Dimensions of mold component (e.g., fixed plate) are shown in the form for mold plate mode generation, as shown inThe system loads the plate size required from the mold base. In this way, load up any other necessary standard mold plates that make up the mold subassembly. Subassembly mold model made up of instance plates are shown in Fig. 10Then get loaded other components of subsystems as shown in Fig. 5. Subsystem for selection other components include bolts and washers. The way of components selection are based on a production rules by authors and by company ―D-M-E‖ [25, 26].2.4 Module for mold modeling (core and cavity design and design all residual mold components; module IV)This module is used for CAD modeling of the mold (core and cavity design). This module uses additional software tools for automation creating core and cavity from simulation (reference) model including shrinkage factor of plastics material and automation splitting mold volumes of the fixed and movable plates. The structure of this module is shown in Fig. 11.Additional capability of this module consists of software tools for:& Applying a shrinkage that corresponds to design plastic part, geometry, and molding conditions, which are computed in module for numerical simulation& Make conceptual CAD model for nonstandard plates and mold components& Design impression, inserts, sand cores, sliders and other components that define a shape of molded part& Populate a mold assembly with standard components such as new developed mold base which consists of DME mold base and mold base of enterprises which use this system, and CAD modeling ejector pins, screws, and other components creating corresponding clearance holes& Create runners and waterlines, which dimensions was calculated in module for calculating of parameters of injection molding and mold design calculation and selection& Check interference of components during mold opening, and check the draft surfacesAfter applied dimensions and selection mold components, user loads 3D model of the fixed (core) and movable (cavity) plate. Geometry mold specifications, calculated in the previous module, are automatically integrated into this module, allowing it to generate the final mold assembly. Output from this module receives the complete mold model of the assembly as shown in Fig. 15. Thismodule allowsFig. 11 Subassembly model of moldFig. 12 CAD model of the test Productmodeling of nonstandard and standard mold components that are not contained in the mold base.3 Case studyThe complete theoretical framework of the CAD/CAE-integrated injection mold design system for plastic products was presented in the previous sections. In order to complete this review, the system was entirely tested on a real case study. The system was tested on few examples of similar plastic parts. Based on the general structure of the model of integrated CAD/CAE design system shown in Fig. 1, the authors tested the system on some concrete examples. One of the examples used for verification of the test model of the plastic part is shown in Fig. 12.The module for the numerical simulation of injection molding process defines the optimal location for setting gating subsystem. Dark blue regions indicate the optimal position for setting gating subsystem as shown in Fig. 13.Based on dimensions, shape, material of the case study product (Fig. 11), optimal gating subsystem location (Fig. 13), and injection molding parameters (Table 1), the simulation model shown in Fig. 14 was generated.One of the rules for defining simulation model gate for numerical simulation:IF (tunnel, plastic material, mass) THEN prediction dimension (upper tunnel, length, diameter1, diameter2, radius, angle, etc.)Part of the output results from module II, which are used in module III are shown in Table 1.Fig. 13 Optimal gating subsystem location in the partTable 1 Part of the output results from the module for the numerical simulation of injection molding processMaterial grade and material supplier Acrylonitrile butadiene styrene 780(ABS 780),Kumho Chemicals Inc.Max injection pressure 100 MPaMold temperature 60°C ili 40Melt Temperature 230°CInjection Time 0,39 s 0,2 sInjection Pressure 27,93 MPaRecommended ejection temperature 79°CModulus of elasticity, flow direction for ABS 780 2,600 MPaModulus of elasticity, transverse direction for ABS 780 2,600 MPaPoision ratio in all directions for ABS 780 0.38Shear modulus for ABS 780 942 MPaDensity in liquid state 0.94032 g/cm3Density in solid state 1.047 g/cm3In module III, the system calculates clamping force F=27.9 kN (Fig. 3), cooling channel diameter d KT=6 mm, cooling channel length lKT090 mm (Fig. 4). Given the shape and dimensions of the simulation model, square shape of mold with normal performance was selected as shown in Fig. 5. Selected mold assembly standard series: 1,616, length and width of mold housing 156×156 mm as shown in Fig. 8. In the segment of calculation shown in Fig. 8, mold design system panel recommends the following mold plates:& Top clamping plate N03-1616-20& Bottom clamping plate N04-1616-20& Fixed mold plate (core plate) N10A-1616-36& Movable plate (cavity plate) N10B-1616-36& Support plate N20-1616-26& Risers N30-1616-46& Ejector retainer plate N40-1616-10& Ejector plate N50-1616-12After finishing the fixed and movable mold plates from the standpoint of CAD modeling core and cavity plates, cooling channel, followed by manual selection of other mold standard components such as sprue bush, locating ring, guide pins, guide bush, leading bushing guide, spacer plates, screws (M4×10, M10×100, M10×30, M6×16, M10×30, etc.) and modeling nonstandard mold components (if any) ejector pins, ejector holes, inserts etc. A complete model of the mold assembly with tested simulation model is shown in Fig. 15.Fig. 14 Simulation model of plastic partFig. 15 Model of the mold assembly with tested simulation model4 ConclusionThe objective of this research was to develop a CAD/CAE integrated system for mold design which is based on Pro/ ENGINEER system and uses specially designed and developed modules for mold design. This paper presents a software solution for multiple cavity mold of identical molding parts, the so-called one product mold. The system is dedicated to design of normal types of molds for products whose length and width are substantially greater than product height, i.e., the system is customized for special requirements of mold manufacturers. The proposed system allows full control over CAD/CAE feature parameters which enables convenient and rapid mold modification. The described CAD/CAE modules are feature-based, parametric, based on solid models, and object oriented. The module for numerical simulation of injection molding allows the determination selection of injection molding parameters. The module for calculation of parameters of injection molding process and mold design calculation and selection improves design Fig. 15 Model of the mold assembly with tested simulation model faster, reduces mold design errors, and provides geometric and precision information necessary for complete mold design. The knowledge base of the system can be accessed by mold designers through interactive modules so that their own intelligence and experience can also be incorporated into the total mold design. Manufacture of the part confirms that the developed CAD/CAE system provides correct results and proves to be a confident software tool.Future research will be directed towards three main goals. The first is to develop a system for automation of family mold design. Another line of research is the integration with CAPP system for plastic injection molds manufacturing developed at the Faculty of Technical Sciences. Finally, following current trends in this area, a collaborative system using web technologies and blackboard architecture shall be designed and implemented.塑料制品的CAD / CAE集成的注塑模具设计系统摘要：模具设计是一个知识密集的过程。

塑料注射成型设计外文文献翻译、中英文翻译、外文翻译

Injection MoldingMany different processes are used to transform plastic granules，powders，and liquids into final product．The plastic material is in moldable form，and is adaptable to various forming methods．In most cases thermoplastic materials are suitable for certain processes while thermosetting materials require other methods of forming．This is recognized by the fact that thermoplastics are usually heated to a soft state and then reshaped before cooling．Theromosets，on the other hand have not yet been polymerized before processing，and the chemical reaction takes place during the process，usually through heat，a catalyst，or pressure．It is important to remember this concept while studying the plastics manufacturing processes and the polymers used．Injection molding is by far the most widely used process of forming thermoplastic materials．It is also one of the oldest．Currently injection molding accounts for 30％of all plastics resin consumption．Since raw material can be converted by a single procedure，injection molding is suitable for mass production of plastics articles and automated one-step production of complex geometries．In most cases，finishing is not necessary．Typical products include toys，automotive parts，household articles，and consumer electronics goods．Since injection molding has a number of interdependent variables，it is a process of considerable complexity．The success of the injection molding operation is dependent not only in the proper setup of the machine variables，but also on eliminating shot—to—shot variations that are caused by the machine hydraulics，barrel temperature variations，and changes in material viscosity．Increasing shot-to-shot repeatability of machine variables helps produce parts with tighter tolerance，lowers the level of rejects，and increases product quality ( i．e．，appearance and serviceability)．The principal objective of any molding operation is the manufacture of products：to a specific quality level，in the shortest time，and using a repeatable and fully automatic cycle,molders strive to reduce or eliminate rejected parts in molding production．②For injection molding of high precision optical parts，or parts with a high added value such as appliance cases，the payoff of reduced rejects is high (Fig．4．2．1)．A typical injection molding cycle or sequence consists of five phases：①Injection or mold filling②Packing or compression③Holding④Cooling⑤Part ejectionFig.4.2.1 Injection molding processPlastic granules are fed into the hopper and through an opening in the injection cylinder where they are carried forward by the rotating screw．The rotation of the screw forces the granules under high pressure against the heated walls of the cylinder causing them to melt．As the pressure builds up，the rotating screw is forced backward until enough plastic has accumulated to make the shot．he injection ram(or screw)forces molten plastic from the barrel，through the nozzle，sprue and runner system，and finally into the mold cavities．During injection the mold cavity is filled volumetrically．When the plastic contacts the colc mold surfaces，it solidifies(freezes)rapidly to produce the skin layer．Since the core remains in the molten state，plastic flows through the core to complete mold filling．Typically，the cavity，is filled to 9 5％～9 8％during injection．Then the molding process is switched over to the packing phaseEven as the cavity is filled，the molten plastic begins to cool．Since the cooling plastic contracts or shrinks，it gives rise to defects such as sink marks，voids，and dimensional instabilities．③To compensate for shrinkage，addition plastic is forced into the cavity．Oncethe cavity is packed，pressure applied to the melt prevents molten plastic inside the cavity from back flowing out through the gate．The pressure must be applied until the gate solidifies．The process can be divided into two steps (packing and holding) or may be encompassed in one step (holding or second stage)．During packing，melt forced into the cavity by the packing pressure compensates for shrinkage．With holding the pressure merely prevents back flow of the polymer melt．After the holding stage is completed，the cooling phase starts．During cooling，the part is held in the mold for specified period．The duration of the cooling phase depends primarily on the material properties and the part thickness．Typically，the part temperature must cool below the material’s ejection temperature．While cooling the part，the machine plasticates melt for the next cycle．The polymer is subjected to shearing action as well as the condition of the energy from the heater bands．Once the shot is made，plastication ceases．This should occur immediately before the end of the cooling phase．Then the mold opens and the part is ejected．Blow MoldingThe rapid growth in the use of advanced materials in a large number of highly demanding automotive,electronic and cunsumer goods applications has promoted the development of new and more complex material forming processes. In the last twenty years injection molding and blow molding have seen a rapid growth due to the development of new application and packaging industries,. this success can be traced to the optimization of existing processes and to the development of new processing techniques employing novel concepts, injection molding has seen the introduction of techniques such as co-injection ,gas assisted injection molding ,lost core molding and injection/compression.(a)Parison extrusion stage (b)Clamping and blowing stageFig.4.2.2 Extrusion blow moldingBlow molding has been able to deal with much more complex parts through the development of 3D and sequential blow molding , complex molds for deepdrawn parts and cryogenic mold cooling . The introduction of new materials has also made possible the production of parts having multilayer structureThe complexity of these new molding techniques calls for a much better understanding of the material behavior during the basic stages of the process and its relation to the properies and performance of the final part, which are directly dependent upon die and mold designs and on the operating conditions during extrusion , injection ,inflation and cooling in the mold. It is in these areas that the computer simulation fot the coupled phenoment of fluid flow and heat transfer has proven to be a very valuable tool for the equipment manufacturer,mold designer and process engineer!Blow molding processBlow molding can be carried reciprocating screw injection machine．About either on an extruder or asection of molten polymer tubing (parsion) is extruded into an open mold．By means of compressed air or steam the plastic is then blown into the configuration of the mold．This technique is widely used for the manufacture of bottles and similar articles．In the case of large articles，such as liter beverage bottles，the parison may previously have beeninjection molded and oriented to provide additional strength to the final blown piece．In the extrusion blow molding process(Fig．4．2．2)，the raw material is fed to a plasticating extruder in granular or pellet form．The plastic is melted by heat which is transferred through the barrel by the shearing motion of the extruder screw．The helical flights of the screw change configuration along its length from input to output(solids conveying,melting and metering sections)to assure a uniformly homogeneous melt at the screw tip．In continuous extrusion blow molding，the screw feeds the melt directly into the head-die assembly．The meit flows around the mandrel and into an annular die of the convergent or divergent type．A hollow tube or“parison”is extruded continuouslv and cut at preset time intervals for transfer into the blow mold．In the case of intermittent extrusion blow molding，the extruder feeds the material to an accumulator／head device．Once the desired volume has accumulated a ram or plunger pushes the material rapidly through the head-die assembly．The mold clamp mechanism does not need to transfer to a blowing station．The next parison is only extruded after the part is blown，cooled and removed from the mold．Once a parison of the desired length has been formed，the mold is closed and the parison is inflated by internal air introduced through the die-head assembly．The mold walls are vented，and a vacuum may be applied．The molten polymer is thus forced to conform to the shape of the mold cavity．The article iS then cooled，solidified and ej ected from the mold．In both methods the annular die may be designed to incorporate a hydraulic mechanism to vary or program the annular gap size．In this way，the extrusion process can be programmed to impart a specific wall thickness distribution or controlled weight to the parison．Injection／stretch blow molding(Fig．4．2．3)is a two—stage process．In the first stage，the material is injection molded around a core rod to form a preform．In the second stage，the preform is then stretched through the action of a stretch rod，inflated and cooled in much the same manner as in the extrusion blow molding process．The result is a lighter product biaxially oriented in the axial and radial directions．Biaxial orientation provides increasedtensile strength(top load)，less gas，liquid and odour permeation due to an increased molecular alignment and improved drop impact，clarity and light weighting of the container．Injection ／stretch blow molding also produces scrap—free，close-tolerance，completely finished bottles or containers that require no secondary operations．Preform design and its relationship to the final container properties remain one of the most critical aspects of the process．The part thickness distribution has to be mapped onto the preform and through the knowledge of the material properties (degree of crystallinity and shrinkage after molding；stretching characteristics and their temperature dependence among others) the preform dimensions(form and thickness distribution)can be established．(a)P reform injection stage (b)Stretching and blowing stagesFig.4.2.3 Injection/stretch blow molding塑料注射成型许多不同的加工过程习惯于把塑料颗粒、粉末和液体转化成最终产品。

注塑模具设计技术中英文对照外文翻译文献

中英文资料对照外文翻译英文：Design and Technology of the Injection Mold1、3D solid model to replace the center layer modelThe traditional injection molding simulation software based on products of the center layer model. The user must first be thin-walled plastic products abstract into approximate plane and curved surface, the surface is called the center layer. In the center layer to generate two-dimensional planar triangular meshes, the use of these two-dimensional triangular mesh finite element method, and the final result of the analysis in the surface display. Injection product model using3D solid model, the two models are inconsistent, two modeling inevitable. But because of injection molding product shape is complex and diverse, the myriads of changes from athree-dimensional entity, abstraction of the center layer is a very difficult job, extraction process is very cumbersome and time-consuming, so the design of simulation software have fear of difficulty, it has become widely used in injection molding simulation software the bottleneck.HSCAE3D is largely accepted3D solid / surface model of the STL file format. Now the mainstream CAD/CAM system, such as UG, Pro/ENGINEER, CATIA and SolidWorks, can output high quality STL format file. That is to say, the user can use any commercial CAD/CAE systems to generate the desired products3D geometric model of the STL format file, HSCAE3D can automatically add the STL file into a finite element mesh model, through the surface matching and introduction of a new boundary conditions to ensure coordination of corresponding surface flow, based on3D solid model of analysis, and display of three-dimensional analysis results, replacing the center layer simulation technology to abstract the center layer, and then generate mesh this complicated steps, broke through system simulation application bottlenecks, greatly reducing the burden of user modeling, reduces the technical requirement of the user, the user training time from the past few weeks shorter for a fewhours. Figure 1 is based on the central layer model and surface model based on 3D solid / flow analysis simulation comparison chart.2、Finite element, finite difference, the control volume methodsInjection molding products are thin products, products in the thickness direction of size is much smaller than the other two dimensions, temperature and other physical quantities in the thickness direction of the change is very large, if the use of a simple finite element and finite difference method will cause analysis time is too long, can not meet the actual needs of mold design and manufacturing. We in the flow plane by using finite element method, the thickness direction by using finite difference method, were established and plane flow and thickness directions corresponding to the size of the grid and coupling, while the accuracy is guaranteed under the premise of the calculation speed to meet the need of engineering application, and using the control volume method is solved. The moving boundary problem in. For internal and external correspondence surface differences between products, can be divided into two parts the volume, and respectively formed the control equation, the junction of interpolation to ensure thatthe two part harmony contrast.3、Numerical analysis and artificial intelligence technologyOptimization of injection molding process parameters has been overwhelming majority of mold design staff concerns, the traditional CAE software while in computer simulation of a designated under the conditions of the injection molding conditions, but is unable to automatically optimize the technical parameters. Using CAE software personnel must be set to different process conditions were multiple CAE analysis, combined with practical experience in the program were compared between, can get satisfactory process scheme. At the same time, the parts after the CAE analysis, the system will generate a large amount of information about the project ( product, process, analyzes the results ), which often results in a variety of data form, requiring the user to have the analysis and understanding of the results of CAE analysis ability, so the traditional CAE software is a kind of passive computational tools, can provide users with intuitionistic, effective engineering conclusion, to software users demand is too high, the influence of CAE system in the larger scope of application and popularization. In view of the above, HSCAE3D software in the original CAE system based on accurate calculationfunction, the knowledge engineering technology is introduced the system development, the use of artificial intelligence is the ability of thinking and reasoning, instead of the user to complete a large number of information analysis and processing work, directly provide guiding significance for the process of conclusions and recommendations, effectively solve the CAE of the complexity of the system and the requirements of the users of the contradiction between, shortening of the CAE system and the distance between the user, the simulation software by traditional " passive" computational tools to " active" optimization system. HSCAE3D system artificial intelligence technology will be applied to the initial design, the results of the analysis of CAE interpretation and evaluation, improvement and optimization analysis of3 aspects.译文：注塑模具设计的技术1．用三维实体模型取代中心层模型传统的注塑成形仿真软件基于制品的中心层模型。

注射注塑模具外文翻译外文文献翻译、中英文翻译、外文翻译

外文资料翻译系部：专业：姓名：学号：外文出处：dvanced English literacy course（用外文写）附件：指导老师评语签名：年月日第一篇译文（中文）2.3注射模2.3.1注射模塑注塑主要用于热塑性制件的生产，它也是最古老的塑料成型方式之一。

目前，注塑占所有塑料树脂消费的30%。

典型的注塑产品主要有杯子器具、容器、机架、工具手柄、旋钮（球形捏手）、电器和通讯部件（如电话接收器），玩具和铅管制造装置。

聚合物熔体因其较高的分子质量而具有很高的粘性；它们不能像金属一样在重力流的作用下直接被倒入模具中，而是需要在高压的作用下强行注入模具中。

因此当一个金属铸件的机械性能主要由模壁热传递的速率决定，这决定了最终铸件的晶粒度和纤维取向，也决定了注塑时熔体注入时的高压产生强大的剪切力是物料中分子取向的主要决定力量。

由此所知，成品的机械性能主要受注射条件和在模具中的冷却条件影响。

注塑已经被应用于热塑性塑料和热固性塑料、泡沫部分，而且也已经被改良用于生产反应注塑过程，在此过程中，一个热固树脂系统的两个组成部分在模具中同时被注射填充，然后迅速聚合。

然而大多数注塑被用热塑性塑料上，接下来的讨论就集中在这样的模具上。

典型的注塑周期或流程包括五个阶段（见图2-1）：（1）注射或模具填充；（2）填充或压紧；（3）定型；（4）冷却；（5）零件顶出。

图2-1 注塑流程塑料芯块（或粉末）被装入进料斗，穿过一条在注射料筒中通过旋转螺杆的作用下塑料芯块（或粉末）被向前推进的通道。

螺杆的旋转迫使这些芯块在高压下对抗使它们受热融化的料筒加热壁。

加热温度在265至500华氏度之间。

随着压力增强，旋转螺杆被推向后压直到积累了足够的塑料能够发射。

注射活塞迫使熔融塑料从料筒，通过喷嘴、浇口和流道系统，最后进入模具型腔。

在注塑过程中，模具型腔被完全充满。

当塑料接触冰冷的模具表面，便迅速固化形成表层。

由于型芯还处于熔融状态，塑料流经型芯来完成模具的填充。

外文原文(注塑模具设计文献翻译)

Effect of gate size on the melt ﬁlling behavior and residual stress of injection moldedpartsPengcheng Xie a ,Fengxia Guo a ,Zhiwei Jiao a ,Yumei Ding a ,Weimin Yang a ,b ,⇑a College of Mechanical and Electrical Engineering,Beijing University of Chemical Technology,Beijing 100029,ChinabState Key Laboratory of Organic–Inorganic Composites,Beijing University of Chemical Technology,Beijing 100029,Chinaa r t i c l e i n f o Article history:Received 8March 2013Accepted 28June 2013Available online 20July 2013Keywords:MoldingVisualization Flow behavior Residual stressa b s t r a c tThis paper studies the effects of gate size on the cavity ﬁlling pattern and residual stress of injection molded parts.A total of three rectangular gates with different sizes were used.Experiments were carried out by using a dynamic visualization system.A ﬂow visualization mold was specially designed and made for this study.A high-speed video camera was used to record the mold ﬁlling phenomena of cavities with different gate size and different processing parameters.In addition,a Stress Viewer was used to charac-terize the residual stress of molded samples.It was found that the undersized gate has many adverse effects on the ﬁlling behavior and residual stress of molded parts.With a larger gate,the cavity will be ﬁlled faster and residual stress of parts may be smaller.The result of the study also indicates that nozzle temperature and injection rate can signiﬁcantly affect the above two aspects.Ó2013Elsevier Ltd.All rights reserved.1.IntroductionGating system design is a key link in the process of injection mold design,because as a channel to connect the runner and the cavity,the gate plays a very important role.The design of gate not only affects the melt ﬁlling process,but also concerns the demolding process and separation of products and waste,thus affecting the production costs and beneﬁts [1].Gate size as an essential aspect of gate design has very important inﬂuence on the quality of part.A gate with suitable dimension should be able to ensure the plastic ﬁlling with fast speed and good liquidity [2].And at the packing stage,gate must remain open long enough to inject additional material into the cavity for shrinkage-compensating.Generally,the gate size is established by experience.Cross-sec-tion of gate is typically smaller than that of the runner and parts,thus parts can be easily separated from the runner without leaving a visible scar on the part.In addition,when the material in the gate drops below the freeze temperature,there is the end of packing,therefore,the gate dimension controls the packing time.From these points of view,the overlarge gate is not desirable.In recent years,a large number of studies on gate design were carried out.But there are limited published works on studies relat-ing to design of gate size:Tor et al.[2]used ﬁve rectangular gateswith different ratio of width and depth to the impacts of gate size on the quality of powder injection molding.By performing the analysis of weight and density on the samples molded for each of the ﬁve gates,they evaluated the impact of different gate size.Shen et al.[3]analyzed the optimal gate design of thin-walled injection molding by using control volume ﬁnite element method.Xie and Ziegmann [4]investigated the effect of gate dimension on micro injection molded weld line strength with polypropylene (PP)and high-density polyethylene (HDPE)and found out some relation-ship between gate size and the quality of micro-molded part.This paper aims to intuitively display the inﬂuence of gate size on melt ﬂow behavior in cavity,as well as the relationship between gate size and residual stress of parts.As moldings are used in wider areas,higher requirements for precision of products have been constantly put forward.How to suppress the generation of product defects (e.g.jet,weld lines,air bubbles,ﬂash,crazing,etc.)and maximize the dimensional accuracy of products has been an important subject for researchers.Observing the ﬂow behavior as an effective method could help people know the generation princi-ple of defects,and further to ﬁnd out the causes and even the solu-tions [5].The emergence of visualization injection molding method applied an effective way for observing the phenomenon of melt ﬂow in the mold.Injection molding visualization technology is a technology that the injection molding process can be directly ob-served.It is essentially adding a system that can real-time monitor-ing the ﬁlling process and reproducing the melt ﬂow behavior in a conventional injection molding process,thus making the injection molding process from the traditional sense of ‘‘invisible’’becomes ‘‘visualization’’and ‘‘repeatable’’.Up to now,visualization method0261-3069/$-see front matter Ó2013Elsevier Ltd.All rights reserved./10.1016/j.matdes.2013.06.071⇑Corresponding author at:College of Mechanical and Electrical Engineering,Beijing University of Chemical Technology,Beijing 100029,China.Tel./fax:+861064434734.E-mail address:yangwm@ (W.M Yang).has been widely used in multiple studies of injection.Yokoi has carried out a lot of research by this technique,for example,the study of molding process of two-color products,observation of ﬂow front behavior duringﬁlling process with two-axis tracking system,analysis of thermoset phenolic resinﬂow behavior by Gate-Magnetization Method,and the study of meltﬁlling disci-pline of ultra-high speed injection molding[6–10],etc.In addition, by this method,Liu and Wu[11]compared the difference ofﬁlling process and molding parts between water-assisted and gas-as-sisted injection molding.Mehdi et al.[12]studied the bubbledynamics in foam injection molding.However,the visualization technology being applied to the gate size has not yet been found, in view of the successful application of it in above-mentioned areas,as well as the signiﬁcant advantage it had shown,this study will use visualization techniques as one of the main means of research.Besides,defects in the products,such as warping and shrinkage, are detrimental to the quality and accuracy of the products[13]. Actually,an important factor causing these defects is residual stress.In general,the residual stress of injection molded products are divided into two Categories.One is the thermal residual stress, which is resulting during cooling period in the mold and after demolding[14].The other one is referred as residualﬂow stresses, which is due to the shear and normal stresses duringﬁlling and packing.Flow-induced stress is smaller than the former,but it could induce anisotropy of optical and some mechanical properties because of different molecular orientation in the directions of par-allel and perpendicular to theﬂow direction[15].Residual stress is not only the main cause of dimensional and shape inaccuracies of molded parts,but also responsible for environmental stress crack-ing[16,17].The dimension of gate inﬂuences the orientation of polymer molecule,ﬁbers,and the mechanical and physical proper-ties of molding parts[18,19].Therefore,through comparing the residual stress of the products can provide the basis for the choice of gate size.Residual birefringence could be a valid measuring method for the polymer molecular orientation and residual stress [20],but it also can reﬂect a microscopic morphological structure of polymer products[21].Friedl[22]considered that the refractive index essentially contains all the information ofstatus characteristics of transparent injection products.In this paper,the visualization method was used toﬂow behavior in the case of different gate size.Throughthe differences ofﬂow behavior with three gates underof injection parameters,the relationship between gatemeltﬁlling process will be drawn.And then,be used to measure the residual stresses in the molding experiment will be performed by Photo-elastic,whicheffect that the induced stresses inside a material willincoming light and form an interaction pattern.Thisbe related to the stress level and distribution inside the2.Experimental procedureThe injection experiment was conducted by the means injection molding.The emergence of visualizationing method applied an effective way for observing thenon of meltﬂow in the mold[5].The visual systemstudy including a injection molding machine,a visual mold,a high speed camera,a light and a data acquisition device.2.1.MaterialMaterial used in this study is an injection molding graded Polypropylene(PP,ST868M,from Chemical LCY,Taiwan),which is a random copolymer with ultra-high transparency,and its properties are listed in Table1.The recommended processing temperature ranges of190–270°C and the mold temperature is recommended between20and50°C.2.2.Part geometry and mold designThe mold cavity used in this paper is a tensile specimen with single gate.The geometries and dimensions of the tensile speci-mens were shown in Fig.1,which were designed and manufac-tured according to ISO527-2:2012[23].The gate of cavity is replaceable,three gates with different dimensions have been adopted in the experiment.Concretely,those gates have the same length(2mm)but different width and depth.According to the cross section size,they were respectively named as gate S(small), gate M(middle)and gate L(large),the actual sizes are shown in Ta-ble2.The middle gate size was selected based on experience val-ues,and then as the standard.The length and width of small gate and large gate were proportional changed and rounded.In order to facilitate the comparison,the small gate was made as small as possible,the cross-sectional edge length was as1/3times as the middle gate and into an integer of1Â1.Meanwhile,the large gate was expanded by the ratio of4/3times as the gate M,andﬁnal rounded to4Â3.Fig.2shows the photo of cavity plate used in the study,the cav-ity is processed on a removable patch,which could be tightly pressed on theﬁxed mold plate by positive pressure.When replac-ing the mold,people just need to loosen the screw then the embed-Table1General property of PP used in this study.Property Unit Globalene ST868M Density g/cm30.899MFI(meltﬂow rate)g/10cm18(230/2.16)Shrinkage% 1.3Tensile stress at yield MPa28Tensile strain at yield%12Heat deﬂection temperature°C88Table2Gate dimensions used in the experimental mold.Gate Small Middle Large Width(mm)134Depth(mm)1 2.53Length(mm)222Fig.1.Dimensions of tensile specimen.P.Xie et al./Materials and Design53(2014)366–372367the plastic molding processing is carried out in a closed ﬂow chan-nel and cavity,the process of melt,mold ﬁlling,solidiﬁcation and cooling are all invisible.Different to the conventional mold whose cavity is surrounded by metal,visual mold changed the cavity wall on the moving platen into a transparent quartz glass,and placed a mirror at a 45°angle in the other side of the glass.By the reﬂection of light,the phenomenon in the cavity can be observed from the outside.The rectangle in Fig.2shows the area that could be seen through the monitoring window.As shown in the ﬁgure,the length of monitoring window is smaller than the length of the article,so it to see the complete ﬁlling process through study.Fig.3shows the mold schematic.the melt ﬁlling process is nearly a transient the process to be seen by the naked eye This paper used a high-speed camera whose reach 17,500frames per second,and each moment of the ﬁlling process could be recorded clearly by it.The devices of visualization experiment are shown in Fig.4.2.3.Injection moldingAll specimens were prepared on an electric injection molding machine (GSK AE80).The maximum clamping force is 80tons,screw diameter is 32mm.The maximum injection velocity and volume can be provided is 300mm/s and 101cm 3.During the course of the experiment,corresponding to each set of experimen-tal parameters with different gates,more than 10shots were made before shooting to ensure that the process was stable.If no signiﬁ-cation variation was observed during these runs,high-speed cam-era would be used to capture the melt ﬁlling process.Each set of parameters was shot ﬁve times,and the ﬁve specimens were col-lected for internal stress test.Table 3shows the experimental parameters and corresponding number.The packing pressure was always set to 80%of injection pressure,and packing time was 5s.The melting temperature was 240°C and mold tempera-ture was constantly at 35°C,original nozzle temperature was 190°C.3.Results discussion and analysis 3.1.Filling behaviorFig.5shows the ﬂow behavior of melt front in the case of parameter (5)with gate S.In the initial stage of melt into the cav-ity,a small amount of material was straightly injected into the cav-ity and jetting occurred.And because of the decrease of temperature,the viscosity increased and the ﬂuidity is reduced after the melt had ﬂown through channel to the gate,a temporary ﬁlling hysteresis generated.Until a large enough pressure had been gradually built up,the low-temperature melt would be promoted into the cavity and moved forward,then the subsequent melt would ﬂow smoothly through the gate and ﬁll the cavity at a high-er speed.During the experiment process,it was found that sometimes the products obtained with gate S may be not fully formed,and increasing the rate and injection pressure can not completely solve the problem.The main reason is that the material in gate S had fro-zen before the cavity was ﬁlled completely.In order to obtain the full ﬁlled specimen,the method of improving the nozzle tempera-ture was tried,and the results showed that the nozzle temperature was a signiﬁcant impact factor on the ﬁlling volume of small gate cavity.Fig.6is the ﬁlling volume of the parts shaped in the case of different injection pressure and nozzle temperature,it is obvious that the higher temperature of the nozzle,the greater the ﬁlling volume.The reason is that if the nozzle temperature is increased,the temperature of melt near the small gate will rise,thereby extending the gate solidiﬁcation time,so that the melt ﬁlling quan-tity increases.Besides,increasing the injection pressure can also help to improve the ﬁlling volume.When using gate M and gate L,the melt fronts were smooth arcs,and there was no jetting or ﬁlling hysteresis occurred in the ﬁlling process.As shown in Fig.7,solid lines shows the regionFig.4.The equipments of visualization experiment.Fig.2.Photo of cavity plate.Table 3Experimental data and corresponding number.Inj.P (MPa)Inj.V (mm/s)408012010(1)(4)(7)30(2)(5)(8)50(3)(6)(9)Fig.3.Schematic of the visual mold.Design 53(2014)366–372can be directly observed,the wave front curve was derived directly from tracing the video capture,the contour shown in dashed line was inferred according to the ﬂow pattern of the preceding para-graph.Through comparing between three schematic diagrams,it can be found that under the same processing parameters,a larger gate may cause a higher ﬁlling speed and there was hardly any short shot parts generated with gate M and gate L when the nozzle temperature was 190°C.The reason is that the volume ﬂow rate of a large gate is generally higher than a small gate when the molding process is conducted in the same condition.As shown in Fig.8,through comparing the ﬁlling processes under different conditions,it can be concluded that the larger set of injection speed resulted in the faster ﬁlling rate.And there was no obvious relationship be-tween ﬁlling rate with injection pressure (Fig.9).On the whole,undersized gate like gate S will cause jetting and low ﬁlling speed.If molding process is conducted in condition of low injection rate or high injection pressure,the defect of shortshot will be able to generate.Therefore,for the ﬁlling behavior,undersized gate is disadvantageous.3.2.Residual stressThe residual stress in the specimens was examined by Stress Viewer R5.1(by Moldex3D,Fig.10),which is an instrument that could non-destructively and qualitatively observe the internal stress of transparent plastic parts.The instrument works by Brew-ster’s law of photo-elasticity.It uses the photo-elastic properties of plastic under stress to observe the variations of material birefrin-gence.When placing a transparent plastic sample between two polarized sheets and shining polarized light on it,the components of the light wave that are parallel and perpendicular to the direc-tion of the stress will propagate through the plastic with different speeds.Color fringes can be observed correspond to different speeds at that point,which in turn correspond to stress level,theFig.7.Filling process with three gates in the case of parameters (5).Fig.5.Filling process with gate S in the case of parameter (5).Fig.6.Specimens shaped by gate S with different nozzle temperature and injection pressure.principle is shown in Fig.11.From the color fringes patterns,the areas with higher density of color fringe lines higher stress inside can be learned.For a polymer material which has been subjected to stress and generated stress deformation,its refractive index of the light in the space will have a directional difference,in another words,the stress components of the plastic material in each directions are dif-ferent.As a result,the refractive index in these directions will also be different,and the difference will be proportional to the the for-mer.Therefore,by observing the light and dark fringes that were presented due to the different refractive index,the distribution and magnitude of residual stress can be known directly.With theoretic analysis and visualization techniques,Du et al.[24]once took rectangular plate cavity for the study,and observed the dynamic evolution process of residual stress during melt ﬁlling.They concluded that the residual stress near the point gate was sig-niﬁcantly more than the fan gate.With the reduction of melt tem-perature or the increase of the holding pressure,the residual stress became larger.In this paper,the effects of various gate size andFig.10.Residual stress Viewer.Fig.11.Schematic diagram of birefringence.12.Residual stress distributions of specimens for three gates when injection rate was 30mm/s.9.Melt-ﬂow-length of gate M with the injection speed of 30mms.(T-time,melt ﬂow length)Melt-ﬂow-length of gate M with the injection pressure of 40MPa.(T-time,ﬂow length)parameters(including temperature,injection speed and injection pressure)on the residual stress were studied,and the discussion of the experimental results were as follows.As shown in Fig.12,when the injection rate was30mm/s and the nozzle temperature was190°C,the residual stress of speci-mens for three gates were signiﬁcantly different.For ease of com-parison,the stress region had been divided into four parts according to the shape of the specimen.Stress of specimens shaped with gate S distributed much wider than specimens of the other two gates,the stress concentrations in the region of part2and part 3were particularly pared to gate S,residual stress of specimens shaped with gate M and L was much less than the for-mer.Difference between gate M and gate L was not obvious,but residual orientation,namely frozen in orientation[25,26].The chains with frozen orientation always have a development trend from high energy state to lower energy state,it means they may tend to curl,wound,or recrystallization,this will lead to inconsis-tent alignment direction and further generate internal stresses[26]. Therefore,when the meltﬂow rate is slower,the cooling rate will be faster,then the frozen in orientation will be more serious,thus the residual stress of products will be larger.That is why articles of gate S have the maximum residual stress and L has the minimum.Another set of contrasting results further demonstrate the inﬂu-ence of temperature on the residual stress.As shown in Fig.14,in the case of injection rate of10mm/s,injection pressure of 120MPa,different nozzle temperature caused different residualFig.14.Residual stress distributions of specimens for gate S under different nozzle temperature.Fig.15.Residual stress distributions of specimens molded by gate M.Fig.13.Fig.13.Sketch of chains of a polymeric in different state[27]P.Xie et al./Materials and Design53(2014)366–372371the wall and in the center is larger than when the temperature was low,the cooling rate is uneven,made the difference of segment ori-entation became greater and thus the phenomenon occurred.In general,the residual stress will decline as the temperature rising, which is consistent with the conclusion of Du[24].In addition to the effect of gate size on residual stress,which also can be seen from Fig.12is that injection pressure has no sig-niﬁcantly inﬂuence on the residual stress in this experiment.Fig.15shows the residual stress distribution of specimens molded by gate M.It can be found that the injection rate has a great inﬂuence on the residual stress.When the rate was10mm/ s,the residual stress distribution was the biggest and the difference with each other mainly lied in part1.The smallest stress was gen-erated in the case of50mm/s.This result suggests that a large speed is helpful to reducing the residual stress.Reason is that most of the polymer molecular chains are arranged along theﬂow direc-tion in theﬁlling process.Due to the faster injection rate resulted in the higher shear rate of the melt,it will lead to the higher orien-tation degree of the segment.Therefore,the preference consistency of products segment will be higher,while theﬂow residual stress will be small.From another point of view,due to the high injection rate,the temperature of melt in the cavity is relatively uniformly and high,according to the previous conclusions,it can be known that the thermal residual stress will also be small.Therefore,the total residual stress will be lower when the injection rate is higher.4.ConclusionsAccording to the results of injection molding visualization experiments and observations on residual stress,the following conclusions could be drawn.(1)Gate size is an important factor affecting theﬁlling behavior.The undersized gate will cause jetting and lowﬁlling speed, and is likely to produce short shot products.If the gate is appropriately enlarged,theﬁlling speed,ﬂow stability and integrity of products will all be improved.Moreover,these effects are coupled with processing conditions,altering the injection speed and nozzle temperature will cause the change ofﬁlling behavior.(2)Gate can signiﬁcantly impact the magnitude and distribu-tion of residual stress:A larger gate may generate smaller stress.Besides,the effect of injection speed and temperature on residual stress should not be ignored.The residual stress will be likely to reduce when the melt isﬁlling in a higher speed or a higher nozzle temperature.Through comparing between these three gates,it can be identi-ﬁed in this paper that the undersized gate has many adverse effects on theﬁlling process and the residual stress.However,based on the traditional experience,the gate is not the larger the better.Fur-ther study is needed to be carried out in this aspect. AcknowledgementsThe authors are supported by the Laboratory of Advanced Poly-mer Processing.We gratefully acknowledge CoreTech System Co.,Ltd.(Moldex3D)and GSK CNC Equipment Co.,Ltd.for their gener-ous supply of the devices.Funding was provided by the National Natural Science Foundation of China(Grant Nos.51203009and 21174015).References[1]Pye RGW.Injection Mould Design.Harlow(Longman Scientiﬁc&Technical);1989.p.358.[2]Tor SB,Loh NH,Khor KA,Yoshida H.The effects of gate size in powder injectionmolding.Mater Manuf Processes1997;12(4):629–40.[3]Shen YK,Wu CW,Yuc YF,Chungc HW.Analysis for optimal gate design of thin-walled injection molding.Int Commun Heat Mass Trans2008;35(6):728–34.[4]Xie L,Ziegmann G.Effect of gate dimension on micro injection molded weldline strength with polypropylene(PP)and high-density polyethylene(HDPE).Int J Adv Manuf Technol2010;48(1–4):71–81.[5]Xie PC,Du B,Yan ZY,Ding YM,Yang WM.Visual experiment study on theinﬂuence of mold structure design on injection molding product’s defects.Adv Mater Res2010;87–88:31–5.[6]Yokoi H.Recent development of visualization analysis techniques in injectionmolding.Denso Tech Rev2006;11(2):3–13.[7]Yokoi H,Masuda N,Mitsuhata H.Visualization analysis ofﬂow front behaviorduringﬁlling process of injection mold cavity by two-axis tracking system.J Mater Process Technol2002;130–131:328–33.[8]Ohta T,Yokoi H.Visual analysis of cavityﬁlling and packing process ininjection molding of thermoset phenolic resin by the gate-magnetization method.Polym Eng Sci2001;41(5):806–19.[9]Yokoi H.Visualization and measurement technologies for ultra-high-speedinjection molding phenomena.Prod Res2007;59:483–91.[10]Yoshimura Y,Endo M,Yokoi H.Visualization analysis of meltﬁlling behaviorfrom submarine-gate in ultra-high-speed injection molding.Prod Res 2009;61:985–8.[11]Liu SJ,Wu YC.Dynamic visualization of cavity-ﬁlling process inﬂuid-assistedinjection molding-gas versus water.Polym Test2007;26(2):232–42.[12]Mehdi M,Amir HB,Mohammad Rezavand SA,Amir P.Visualization of bubbledynamics in foam injection molding.J Appl Polym Sci2010;116(6):3346–55.[13]Demirer A,Soydan Y,Kapti AO.An experimental investigation of the effects ofhot runner system on injection moulding process in comparison with conventional runner system.Mater Des2007;28:1467–76.[14]Wang TH,Young WB.Study on residual stresses of thin-walled injectionmolding.Euro Polym J2005;41:2511–7.[15]Zoetelief WF,Douven LFA,Ingen Housz AJ.Residual thermal stresses ininjection molded products.Polym Eng Sci1996;36(14):1886–96.[16]Kamal MR,Lai-Fook RA,Hernandez-Aguilar JR.Residual thermal stresses ininjection moldings of thermoplastics:a theoretical and experimental study.Polym Eng Sci2002;42(5):1098–114.[17]Wimberger-Friedl R,de Bruin JG,Schoo HFM.Residual birefringence inmodiﬁed polycarbonates.Polym Eng Sci2003;43(1):62–70.[18]Fiske T,Gokturk HS,Yazici R,Kalyon DM.Effects ofﬂow induced orientation offerromagnetic particles on relative magnetic permeability of injection molded composites.Polym Eng Sci1997;37(5):826.[19]Yamada K,Tomari K,Ishiaku US,Hamada H.Fracture toughness evaluation ofadjacentﬂow weld line in polystyrene by the SENB method.Polym Eng Sci 2005;45(8):1059–66.[20]Tumbull A,Maxwell AS,Pillai S.Residual stress in polymers evaluation ofmeasurement techniques.J Mater Sci1999;34(3):451–9.[21]Neves NM,Pouzada AS.The use of birefringence for predicting the stiffness ofinjection molded polycarbonate discs.Polym Eng Sci1998;38(10):1770–7. [22]Wimberger-Friedl R.The assessment of orientation,stress and densitydistributions in injection-molded amorphous polymers by optical techniques.Prog Polym Sci1995;20(3):369–99.[23]ISO527-2.Plastics—determination of tensile properties—Part2:Testconditions for moulding and extrusion plastics;2012.[24]Du B.Dynamic visualization experimental study of internal stress on theoptical products.Beijing University of Chemical Technology;2011.[25]Jansen KMB,Flaman AAM.The inﬂuence of surface heating on thebirefringence distribution in injection molded parts.Polym Eng Sci 1994;34(11):898–904.[26]Xu QJ,Yu SW.Calculation of residual stress in injection molded productionmolded products for polymer materials.Chinese J Theor Appl Mech 1998;30:157–67.[27]ten Grotenhuis SM,Piazolo S,Pakula T,Passchier CW,Bons PD.Are polymerssuitable rock analogs?Tectonophysics2002;350(1):35–47.372P.Xie et al./Materials and Design53(2014)366–372。

模具注射成型中英文对照外文翻译文献

中英文对照资料外文翻译Injection MoldingThe basic concept of injection molding revolves around the ability of a thermoplastic material to be softened by heat and to harden when cooled .In most operations ,granular material (the plastic resin) is fed into one end of the cylinder (usually through a feeding device known as a hopper ),heated, and softened(plasticized or plasticated),forced out the other end of the cylinder,while it is still in the form of a melt,through a nozzle into a relatively cool mold held closed under pressure.Here,the melt cools and hardens until fully set-up.The mold is then opened,the piece ejected,and the sequence repeated.Thus,the significant elements of an injection molding machine become :1)the way in which the melt is plasticized (softened) and forced into the mold (called the injection unit);2)the system for opening the mold and closing it under pressure (called the clamping unit);3)the type of mold used;4)themachine controls.The part of an injection-molding machine,which converts a plastic material from a sold phase to homogeneous seni-liguid phase by raising its temperature .This unit maintains the material at a present temperature and force it through the injection unit nozzle into a mold .The plunger is a combination of the injection and plasticizing device in which a heating chamber is mounted between the plunger and mold. This chamber heats the plastic material by conduction .The plunger,on each storke; pushes unmelted plastic material into the chamber ,which in turn forces plastic melt at the front of the chamber out through the nozzleThe part of an injection molding machine in which the mold is mounted,and which provides the motion and force to open and close the mold and to hold the mold close with force during injection .This unit can also provide other features necessary for the effective functioning of the molding operation .Moving plate is the member of the clamping unit,which is moved toward a stationary member.the moving section of the mold is bolted to this moving plate .This member usually includes the ejector holes and moldmounting pattern of blot holes or “T”slots .Stationary plate is the fixed member of the clamping uniton which the stationary section of the mold is bolted .This member usually includes a mold-mounting pattern of boles or “T” slots.Tie rods are member of the clamping force actuating mechanism that serve as the tension member of the clamp when it is holding the mold closed.They also serve as a gutde member for the movable plate .Ejector is a provision in the clamping unit that actuates a mechanism within the mold to eject the molded part(s) from the mold .The ejection actuating force may be applied hydraulically or pneumatically by a cylinder(s) attached to the moving plate ,or mechanically by the opening storke of the moving plate.Methods of melting and injecting the plastic differ from one machine to another and are constantly being improred .couventional machines use a cylinder and piston to do both jobs .This method simplifies machine construction but makes control of injection temperatures and pressures an inherently difficult problem .Other machines use a plastcating extruder to melt the plastic and piston to inject it while some hare been designed to use a screw for both jobs :Nowadays,sixty percent of the machines use a reciprocating screw,35% a plunger (concentrated in the smaller machine size),and 5%a screw pot. Many of the problems connected with in jection molding arisesbecause the densities of polymers change so markedly with temperature and pressure.Athigh temperatures,the density of a polymer is considerably cower than at room temperature,provided the pressure is the same.Therefore,if modls were filled at atmospheric pressure, “shrinkage”would make the molding deviate form the shape of the mold.To compensate for this poor effect, molds are filled at high pressure.The pressure compresses the polymer and allows more materials to flow into the mold,shrinkage is reduced and better quality moldings are produced.Cludes a mold-mounting pattern of bolt holes or “T”slots.Tie rods are members of the clamping force actuating machanism that serve as the tension members of clamp when it is holding the mold closed.Ejector is a provision in the claming unit that actuates a mechanism within the mold to eject themolded part(s) form the mold.The ejection actuating force may be applied hydraulically or pneumatically by a cylinder(s) attached to the moving plate,or mechanically by the opening stroke of the moving plate.The function of a mold is twofold :imparting the desired shape to the plasticized polymer and cooling the injection molded part.It is basically made up of two sets of components :the cavities and cores and the base in which the cavities and coresare mounted. The mold ,which contains one or more cavities,consists of two basic parts :(1) a stationary molds half one the side where the plastic is injected,(2)Amoving half on the closing or ejector side of the machine. The separation between the two mold halves is called the parting line.In some cases the cavity is partly in the stationary and partly in the moving section.The size and weight of the molded parts limit the number of cavities in the mold and also determine the machinery capacity required.The mold components and their functions are as following :(1)Mold Base-Hold cavity(cavities) in fixed ,correctposition relative to machine nozzle .(2)Guide Pins-Maintain Proper alignment of entry into moldintrior .(3)Sprue Bushing(sprue)-Provide means of entry into moldinterior .(4)Runners-Conrey molten plastic from sprue to cavities .(5)Gates-Control flow into cavities.(6)Cavity(female) and Force(male)-Contorl the size,shapeand surface of mold article.(7)Water Channels-Control the temperature of mold surfacesto chill plastic to rigid state.(8)Side (actuated by came,gears or hydrauliccylinders)-Form side holes,slots,undercuts and threaded sections.(9)Vent-Allow the escape of trapped air and gas.(10)Ejector Mechanism (pins,blades,stripper plate)-Ejectrigid molded article form cavity or force.(11)Ejector Return Pins-Return ejector pins to retractedposition as mold closes for next cycle.The distance between the outer cavities and the primary sprue must not be so long that the molten plastic loses too much heat in the runner to fill the outer cavities properly.The cavities should be so arranged around the primary sprue that each receives its full and equal share of the total pressure available,through its own runner system(or the so-called balanced runner system).The requires the shortest possible distance between cavities and primary sprue,equal runner and gate dimension,and uniform colling.注射成型注射成型的基本概念是使热塑性材料在受热时熔融，冷却时硬化，在大部分加工中，粒状材料（即塑料树脂）从料筒的一端（通常通过一个叫做“料斗”的进料装置）送进，受热并熔融（即塑化或增塑），然后当材料还是溶体时，通过一个喷嘴从料筒的另一端挤到一个相对较冷的压和封闭的模子里。

注塑模具中英文对照外文翻译文献

中英文对照资料外文翻译Integrated simulation of the injection molding process withstereolithography moldsAbstract Functional parts are needed for design veriﬁcation testing, ﬁeld trials, customer evaluation, and production planning. By eliminating multiple steps, the creation of the injection mold directly by a rapid prototyping (RP) process holds the best promise of reducing the time and cost needed to mold low-volume quantities of parts. The potential of this integration of injection molding with RP has been demonstrated many times. What is missing is the fundamental understanding of how the modiﬁcations to the mold material and RP manufacturing process impact both the mold design and the injection molding process. In addition, numerical simulation techniques have now become helpful tools of mold designers and process engineers for traditional injection molding. But all current simulation packages for conventional injection molding are no longer applicable to this new type of injection molds, mainly because the property of the mold material changes greatly. In this paper, an integrated approach to accomplish a numerical simulation of injection molding into rapid-prototyped molds is established and a corresponding simulation system is developed. Comparisons with experimental results are employed for veriﬁcation, which show that the present scheme is well suited to handle RP fabricated stereolithography (SL) molds.Keywords Injection molding Numerical simulation Rapid prototyping1 IntroductionIn injection molding, the polymer melt at high temperature is injected into the mold under high pressure [1]. Thus, the mold material needs to have thermal and mechanical properties capable of withstanding the temperatures and pressures of the molding cycle. The focus of many studies has been to create theinjection mold directly by a rapid prototyping (RP) process. By eliminating multiple steps, this method of tooling holds the best promise of reducing the time and cost needed to createlow-volume quantities of parts in a production material. The potential of integrating injection molding with RP technologies has been demonstrated many times. The properties of RP molds are very different from those of traditional metal molds. The key differences are the properties of thermal conductivity and elastic modulus (rigidity). For example, the polymers used in RP-fabricated stereolithography (SL) molds have a thermal conductivity that is less than one thousandth that of an aluminum tool. In using RP technologies to create molds, the entire mold design and injection-molding process parameters need to be modiﬁed and optimized from traditional methodologies due to the completely different tool material. However, there is still not a fundamental understanding of how the modiﬁcations to the mold tooling method and material impact both the mold design and the injection molding process parameters. One cannot obtain reasonable results by simply changing a few material properties in current models. Also, using traditional approaches when making actual parts may be generating sub-optimal results. So there is a dire need to study the interaction between the rapid tooling (RT) process and material and injection molding, so as to establish the mold design criteria and techniques for an RT-oriented injection molding process.In addition, computer simulation is an effective approach for predicting the quality of molded parts. Commercially available simulation packages of the traditional injection molding process have now become routine tools of the mold designer and process engineer [2]. Unfortunately, current simulation programs for conventional injection molding are no longer applicable to RP molds, because of the dramatically dissimilar tool material. For instance, in using the existing simulation software with aluminum and SL molds and comparing with experimental results, though the simulation values of part distortion are reasonable for the aluminum mold, results are unacceptable, with the error exceeding 50%. The distortion during injection molding is due to shrinkage and warpage of the plastic part, as well as the mold. For ordinarily molds, the main factor is the shrinkage and warpage of the plastic part, which is modeled accurately in current simulations. But for RP molds, the distortion of the mold has potentially more inﬂuence, which have been neglected in current models. For instance, [3] used a simple three-step simulation process to consider the mold distortion, which had too much deviation.In this paper, based on the above analysis, a new simulation system for RP molds is developed. The proposed system focuses on predicting part distortion, which is dominating defect in RP-molded parts. The developed simulation can be applied as an evaluation tool for RP mold design and process opti mization. Our simulation system is veriﬁed by an experimental example.Although many materials are available for use in RP technologies, we concentrate on usingstereolithography (SL), the original RP technology, to create polymer molds. The SL process uses photopolymer and laser energy to build a part layer by layer. Using SL takes advantage of both the commercial dominance of SL in the RP industry and the subsequent expertise base that has been developed for creating accurate, high-quality parts. Until recently, SL was primarily used to create physical models for visual inspection and form-ﬁt studies with very limited func-tional applications. However, the newer generation stereolithographic photopolymers have improved dimensional, mechanical and thermal properties making it possible to use them for actual functional molds.2 Integrated simulation of the molding process2.1 MethodologyIn order to simulate the use of an SL mold in the injection molding process, an iterative method is proposed. Different software modules have been developed and used to accomplish this task. The main assumption is that temperature and load boundary conditions cause signiﬁcant distortions in the SL mold. The simulation steps are as follows:1The part geo metry is modeled as a solid model, which is translated to a ﬁle readable by the ﬂow analysis package.2Simulate the mold-ﬁlling process of the melt into a pho topolymer mold, which will output the resulting temperature and pressure proﬁles.3Structural analysis is then performed on the photopolymer mold model using the thermal and load boundary conditions obtained from the previous step, which calculates the distortion that the mold undergo during the injection process.4If the distortion of the mold converges, move to the next step. Otherwise, the distorted mold cavity is then modeled (changes in the dimensions of the cavity after distortion), and returns to the second step to simulate the melt injection into the distorted mold.5The shrinkage and warpage simulation of the injection molded part is then applied, which calculates the ﬁnal distor tions of the molded part.In above simulation ﬂow, there are three basic simulation mod ules.2. 2 Filling simulation of the melt2.2.1 Mathematical modelingIn order to simulate the use of an SL mold in the injection molding process, an iterativemethod is proposed. Different software modules have been developed and used to accomplish this task. The main assumption is that temperature and load boundary conditions cause significant distortions in the SL mold. The simulation steps are as follows:1. The part geometry is modeled as a solid model, which is translated to a file readable by the flow analysis package.2. Simulate the mold-filling process of the melt into a photopolymer mold, which will output the resulting temperature and pressure profiles.3. Structural analysis is then performed on the photopolymer mold model using the thermal and load boundary conditions obtained from the previous step, which calculates the distortion that the mold undergo during the injection process.4. If the distortion of the mold converges, move to the next step. Otherwise, the distorted mold cavity is then modeled (changes in the dimensions of the cavity after distortion), and returns to the second step to simulate the melt injection into the distorted mold.5. The shrinkage and warpage simulation of the injection molded part is then applied, which calculates the final distortions of the molded part.In above simulation flow, there are three basic simulation modules.2.2 Filling simulation of the melt2.2.1 Mathematical modelingComputer simulation techniques have had success in predicting filling behavior in extremely complicated geometries. However, most of the current numerical implementation is based on a hybrid finite-element/finite-difference solution with the middleplane model. The application process of simulation packages based on this model is illustrated in Fig. 2-1. However, unlike the surface/solid model in mold-design CAD systems, the so-called middle-plane (as shown in Fig. 2-1b) is an imaginary arbitrary planar geometry at the middle of the cavity in the gap-wise direction, which should bring about great inconvenience in applications. For example, surface models are commonly used in current RP systems (generally STL file format), so secondary modeling is unavoidable when using simulation packages because the models in the RP and simulation systems are different. Considering these defects, the surface model of the cavity is introduced as datum planes in the simulation, instead of the middle-plane.According to the previous investigations [4–6], fillinggoverning equations for the flow and temperature field can be written as:where x, y are the planar coordinates in the middle-plane, and z is the gap-wise coordinate; u, v,w are the velocity components in the x, y, z directions; u, v are the average whole-gap thicknesses; and η, ρ,CP (T), K(T) represent viscosity, density, specific heat and thermal conductivity of polymer melt, respectively.Fig.2-1 a–d. Schematic procedure of the simulation with middle-plane model. a The 3-D surface model b The middle-plane model c The meshed middle-plane model d The display of the simulation result In addition, boundary conditions in the gap-wise direction can be defined as:where TW is the constant wall temperature (shown in Fig. 2a).Combining Eqs. 1–4 with Eqs. 5–6, it follows that the distributions of the u, v, T, P at z coordinates should be symmetrical, with the mirror axis being z = 0, and consequently the u, v averaged in half-gap thickness is equal to that averaged in wholegap thickness. Based on this characteristic, we can divide the whole cavity into two equal parts in the gap-wise direction, as described by Part I and Part II in Fig. 2b. At the same time, triangular finite elements are generated in the surface(s) of the cavity (at z = 0 in Fig. 2b), instead of the middle-plane (at z = 0 in Fig. 2a). Accordingly, finite-difference increments in the gapwise direction are employed only in the inside of the surface(s) (wall to middle/center-line), which, in Fig. 2b, means from z = 0 to z = b. This is single-sided instead of two-sided with respect to the middle-plane (i.e. from the middle-line to two walls). In addition, the coordinate system is changed from Fig. 2a to Fig. 2b to alter the finite-element/finite-difference scheme, as shown in Fig. 2b. With the above adjustment, governing equations are still Eqs. 1–4. However, the original boundary conditions inthe gapwise direction are rewritten as:Meanwhile, additional boundary conditions must be employed at z = b in order to keep the flows at the juncture of the two parts at the same section coordinate [7]:where subscripts I, II represent the parameters of Part I and Part II, respectively, and Cm-I and Cm-II indicate the moving free melt-fronts of the surfaces of the divided two parts in the filling stage.It should be noted that, unlike conditions Eqs. 7 and 8, ensuring conditions Eqs. 9 and 10 are upheld in numerical implementations becomes more difficult due to the following reasons:1. The surfaces at the same section have been meshed respectively, which leads to a distinctive pattern of finite elements at the same section. Thus, an interpolation operation should be employed for u, v, T, P during the comparison between the two parts at the juncture.2. Because the two parts have respective flow fields with respect to the nodes at point A and point C (as shown in Fig. 2b) at the same section, it is possible to have either both filled or one filled (and one empty). These two cases should be handled separately, averaging the operation for the former, whereas assigning operation for the latter.3. It follows that a small difference between the melt-fronts is permissible. That allowance can be implemented by time allowance control or preferable location allowance control of the melt-front nodes.4. The boundaries of the flow field expand by each melt-front advancement, so it is necessary to check the condition Eq. 10 after each change in the melt-front.5. In view of above-mentioned analysis, the physical parameters at the nodes of the same section should be compared and adjusted, so the information describing finite elements of the same section should be prepared before simulation, that is, the matching operation among the elements should be preformed.Fig. 2a,b. Illustrative of boundary conditions in the gap-wise direction a of the middle-plane model b of thesurface model2.2.2 Numerical implementationPressure field. In modeling viscosity η, which is a function of shear rate, temperature and pressure of melt, the shear-thinning behavior can be well represented by a cross-type model such as:where n corresponds to the power-law index, and τ∗ characterizes the shear stress level of the transition region between the Newtonian and power-law asymptotic limits. In terms of an Arrhenius-type temperature sensitivity and exponential pressure dependence, η0(T, P) can be represented with reasonable accuracy as follows:Equations 11 and 12 constitute a five-constant (n, τ∗, B, Tb, β) representation for viscosity. The shear rate for viscosity calculation is obtained by:Based on the above, we can infer the following filling pressure equation from the governing Eqs. 1–4:where S is calculated by S = b0/(b−z)2η d z. Applying the Galerkin method, the pressure finite-element equation is deduced as:where l_ traverses all elements, including node N, and where I and j represent the local node number in element l_ corresponding to the node number N and N_ in the whole, respectively. The D(l_) ij is calculated as follows:where A(l_) represents triangular finite elements, and L(l_) i is the pressure trial function in finite elements.Temperature field. To determine the temperature profile across the gap, each triangular finite element at the surface is further divided into NZ layers for the finite-difference grid.The left item of the energy equation (Eq. 4) can be expressed as:where TN, j,t represents the temperature of the j layer of node N at time t.The heat conduction item is calculated by:where l traverses all elements, including node N, and i and j represent the local node number in element l corresponding to the node number N and N_ in the whole, respectively.The heat convection item is calculated by:For viscous heat, it follows that:Substituting Eqs. 17–20 into the energy equation (Eq. 4), the temperature equation becomes:2.3 Structural analysis of the moldThe purpose of structural analysis is to predict the deformation occurring in the photopolymer mold due to the thermal and mechanical loads of the filling process. This model is based on a three-dimensional thermoelastic boundary element method (BEM). The BEM is ideally suited for this application because only the deformation of the mold surfaces is of interest. Moreover, the BEM has an advantage over other techniques in that computing effort is not wasted on calculating deformation within the mold.The stresses resulting from the process loads are well within the elastic range of the mold material. Therefore, the mold deformation model is based on a thermoelastic formulation. The thermal and mechanical properties of the mold are assumed to be isotropic and temperature independent.Although the process is cyclic, time-averaged values of temperature and heat flux are used for calculating the mold deformation. Typically, transient temperature variations within a mold have been restricted to regions local to the cavity surface and the nozzle tip [8]. The transients decay sharply with distance from the cavity surface and generally little variation is observed beyond distances as small as 2.5 mm. This suggests that the contribution from the transients to the deformation at the mold block interface is small, and therefore it is reasonable to neglect the transient effects. The steady state temperature field satisfies Laplace’s equation 2T = 0 and the time-averaged boundary conditions. The boundary conditions on the mold surfaces are described in detail by Tang et al. [9]. As for the mechanical boundary conditions, the cavity surface is subjected to the melt pressure, the surfaces of the mold connected to the worktable are fixed in space, and other external surfaces are assumed to be stress free.The derivation of the thermoelastic boundary integral formulation is well known [10]. It is given by:where uk, pk and T are the displacement, traction and temperature,α, ν represent the thermal expansion coefficient and Poisson’s ratio of the material, and r = |y−x|. clk(x) is the surfacecoefficient which depends on the local geometry at x, the orientation of the coordinate frame and Poisson’s ratio for the domain [11]. The fundamental displacement ˜ulk at a point y in the xk direction, in a three-dimensional infinite isotropic elastic domain, results from a unit load concentrated at a point x acting in the xl direction and is of the form:where δlk is the Kronecker delta function and μ is the shear modulus of the mold material.The fundamental traction ˜plk , measured at the point y on a surface with unit normal n, is:Discretizing the surface of the mold into a total of N elements transforms Eq. 22 to:where Γn refers to the n th surface element on the domain.Substituting the appropriate linear shape functions into Eq. 25, the linear boundary element formulation for the mold deformation model is obtained. The equation is applied at each node on the discretized mold surface, thus giving a system of 3N linear equations, where N is the total number of nodes. Each node has eight associated quantities: three components of displacement, three components of traction, a temperature and a heat flux. The steady state thermal model supplies temperature and flux values as known quantities for each node, and of the remaining six quantities, three must be specified. Moreover, the displacement values specified at a certain number of nodes must eliminate the possibility of a rigid-body motion or rigid-body rotation to ensure a non-singular system of equations. The resulting system of equations is assembled into a integrated matrix, which is solved with an iterative solver.2.4 Shrinkage and warpage simulation of the molded partInternal stresses in injection-molded components are the principal cause of shrinkage and warpage. These residual stresses are mainly frozen-in thermal stresses due to inhomogeneous cooling, when surface layers stiffen sooner than the core region, as in free quenching. Based onthe assumption of the linear thermo-elastic and linear thermo-viscoelastic compressible behavior of the polymeric materials, shrinkage and warpage are obtained implicitly using displacement formulations, and the governing equations can be solved numerically using a finite element method.With the basic assumptions of injection molding [12], the components of stress and strain are given by:The deviatoric components of stress and strain, respectively, are given byUsing a similar approach developed by Lee and Rogers [13] for predicting the residual stresses in the tempering of glass, an integral form of the viscoelastic constitutive relationships is used, and the in-plane stresses can be related to the strains by the following equation:Where G1 is the relaxation shear modulus of the material. The dilatational stresses can be related to the strain as follows:Where K is the relaxation bulk modulus of the material, and the definition of α and Θ is:If α(t) = α0, applying Eq. 27 to Eq. 29 results in:Similarly, applying Eq. 31 to Eq. 28 and eliminating strain εxx(z, t) results in:Employing a Laplace transform to Eq. 32, the auxiliary modulus R(ξ) is given by:Using the above constitutive equation (Eq. 33) and simplified forms of the stresses and strains in the mold, the formulation of the residual stress of the injection molded part during the cooling stage is obtain by:Equation 34 can be solved through the application of trapezoidal quadrature. Due to the rapid initial change in the material time, a quasi-numerical procedure is employed for evaluating the integral item. The auxiliary modulus is evaluated numerically by the trapezoidal rule.For warpage analysis, nodal displacements and curvatures for shell elements are expressed as:where [k] is the element stiffness matrix, [Be] is the derivative operator matrix, {d} is the displacements, and {re} is the element load vector which can be evaluated by:The use of a full three-dimensional FEM analysis can achieve accurate warpage results, however, it is cumbersome when the shape of the part is very complicated. In this paper, a twodimensional FEM method, based on shell theory, was used because most injection-molded parts have a sheet-like geometry in which the thickness is much smaller than the other dimensions of the part. Therefore, the part can be regarded as an assembly of flat elements to predict warpage. Each three-node shell element is a combination of a constant strain triangular element (CST) and a discrete Kirchhoff triangular element (DKT), as shown in Fig. 3. Thus, the warpage can be separated into plane-stretching deformation of the CST and plate-bending deformation of the DKT, and correspondingly, the element stiffness matrix to describe warpage can also be divided into the stretching-stiffness matrix and bending-stiffness matrix.Fig. 3a–c. Deformation decomposition of shell element in the local coordinate system. a In-plane stretchingelement b Plate-bending element c Shell element3 Experimental validationTo assess the usefulness of the proposed model and developed program, verification is important. The distortions obtained from the simulation model are compared to the ones from SL injection molding experiments whose data is presented in the literature [8]. A common injection molded part with the dimensions of 36×36×6 mm is considered in the experiment, as shown in Fig. 4. The thickness dimensions of the thin walls and rib are both 1.5 mm; and polypropylene was used as the injection material. The injection machine was a production level ARGURY Hydronica 320-210-750 with the following process parameters: a melt temperature of 250 ◦C; an ambient temperature of 30 ◦C; an injection pressure of 13.79 MPa; an injection time of 3 s; and a cooling time of 48 s. The SL material used, Dupont SOMOSTM 6110 resin, has the ability to resist temperatures of up to 300 ◦C temperatures. As mentioned above, thermal conductivity of the mold is a major factor that differentiates between an SL and a traditional mold. Poor heat transfer in the mold would produce a non-uniform temperature distribution, thus causing warpage that distorts the completed parts. For an SL mold, a longer cycle time would be expected. The method of using a thin shell SL mold backed with a higher thermal conductivity metal (aluminum) was selected to increase thermal conductivity of the SL mold.Fig. 4. Experimental cavity modelFig. 5. A comparison of the distortion variation in the X direction for different thermal conductivity; where “Experimental”, “present”, “three-step”, and “conventional” mean the results of the experimental, the presented simulation, the three-step simulation process and the conventional injection molding simulation, respectively.Fig. 6. Comparison of the distortion variation in the Y direction for different thermal conductivitiesFig. 7. Comparison of the distortion variation in the Z direction for different thermal conductivitiesFig. 8. Comparison of the twist variation for different thermal conductivities For this part, distortion includes the displacements in three directions and the twist (the difference in angle between two initially parallel edges). The validation results are shown in Fig.5 to Fig. 8. These figures also include the distortion values predicted by conventional injection molding simulation and the three-step model reported in [3].4 ConclusionsIn this paper, an integrated model to accomplish the numerical simulation of injection molding into rapid-prototyped molds is established and a corresponding simulation system is developed. For verification, an experiment is also carried out with an RPfabricated SL mold.It is seen that a conventional simulation using current injection molding software breaks down for a photopolymer mold. It is assumed that this is due to the distortion in the mold caused by the temperature and load conditions of injection. The three-step approach also has much deviation. The developed model gives results closer to experimental.Improvement in thermal conductivity of the photopolymer significantly increases part quality. Since the effect of temperature seems to be more dominant than that of pressure (load), an improvement in the thermal conductivity of the photopolymer can improve the part quality significantly.Rapid Prototyping (RP) is a technology makes it possible to manufacture prototypes quickly and inexpensively, regardless of their complexity. Rap id Tooling (RT) is the next step in RP’s steady progress and much work is being done to obtain more accurate tools to define the parameters of the process. Existing simulation tools can not provide the researcher with a useful means of studying relative changes. An integrated model, such as the one presented in this paper, is necessary to obtain accurate predictions of the actual quality of final parts. In the future, we expect to see this work expanded to develop simulations program for injection into RP molds manufactured by other RT processes.References1. Wang KK (1980) System approach to injection molding process. Polym-Plast Technol Eng 14(1):75–93.2. Shelesh-Nezhad K, Siores E (1997) Intelligent system for plastic injection molding process design. J Mater Process Technol 63(1–3):458–462.3. Aluru R, Keefe M, Advani S (2001) Simulation of injection molding into rapid-prototyped molds. Rapid Prototyping J 7(1):42–51.4. Shen SF (1984) Simulation of polymeric flows in the injection molding process. Int J Numer Methods Fluids 4(2):171–184.5. Agassant JF, Alles H, Philipon S, Vincent M (1988) Experimental and theoretical study of the injection molding of thermoplastic materials. Polym Eng Sci 28(7):460–468.6. Chiang HH, Hieber CA, Wang KK (1991) A unified simulation of the filling and post-filling stages in injection molding. Part I: formulation. Polym Eng Sci 31(2):116–124.7. Zhou H, Li D (2001) A numerical simulation of the filling stage in injection molding based on a surface model. Adv Polym Technol 20(2):125–131.8. Himasekhar K, Lottey J, Wang KK (1992) CAE of mold cooling in injection molding using a three-dimensional numerical simulation. J EngInd Trans ASME 114(2):213–221.9. Tang LQ, Pochiraju K, Chassapis C, Manoochehri S (1998) Computeraided optimization approach for the design of injection mold cooling systems. J Mech Des, Trans ASME 120(2):165–174.10. Rizzo FJ, Shippy DJ (1977) An advanced boundary integral equation method for three-dimensional thermoelasticity. Int J Numer Methods Eng 11:1753–1768.11. Hartmann F (1980) Computing the C-matrix in non-smooth boundary points. In: New developments in boundary element methods, CML Publications, Southampton, pp 367–379.12. Chen X, Lama YC, Li DQ (2000) Analysis of thermal residual stress in plastic injection molding. J Mater Process Technol 101(1):275–280.13. Lee EH, Rogers TG (1960) Solution of viscoelastic stress analysis problems using measured creep or relaxation function. J Appl Mech 30(1):127–134.14. Li Y (1997) Studies in direct tooling using stereolithography. Dissertation, University of Delaware, Newark, DE..。

注塑成型的实验研究外文文献翻译、注射模注塑模塑料模具中英文翻译、外文翻译

附录附录1An experimental study of the water-assisted injection molding ofglass fiber filled poly-butylene-terephthalate(PBT) compositesAbstract：The purpose of this report was to experimentally study the water-assisted injection molding process of poly-butylene-terephthalate(PBT) composites. Experiments were carried out on an 80-ton injection-molding machine equipped with a lab scale water injection system,which included a water pump, a pressure accumulator, a water injection pin, a water tank equipped with a temperature regulator,and a control circuit. The materials included virgin PBT and a 15% glass fiber filled PBT composite, and a plate cavity with a rib across center was used. Various processing variables were examined in terms of their influence on the length of water penetration in molded parts, and mechanical property tests were performed on these parts. X-ray diffraction (XRD) was also used to identify the material and structural parameters. Finally, a comparison was made between water-assisted and gas-assisted injection molded parts. It was found that the melt fill pressure, melt temperature, and short shot size were the dominant parameters affecting water penetration behavior.Material at the mold-side exhibited a higher degree of crystallinity than that at the water-side. Parts molded by gas also showed a higher degree of crystallinity than those molded by water. Furthermore, the glass fibers near the surface of molded parts were found to be oriented mostly in the flow direction, but oriented substantially more perpendicular to the flow direction with increasing distance from the skin surface.Keywords: Water assisted injection molding; Glass fiber reinforced poly-butylene-terephthalate (PBT) composites; Processing parameters; B. Mechanical properties; Crystallinity; A. Polymer matrix composites;1. IntroductionWater-assisted injection molding technology [1] has proved itself a breakthrough in the manufacture of plastic parts due to its light weight, faster cycle time, and relatively lower resin cost per part. In the water-assisted injection molding process, the mold cavity is partially filled with the polymer melt followed by the injection of water into the core of the polymer melt. A schematic diagram of the water-assisted injection molding process is illustrated in Fig. 1.Water-assisted injection molding can produce parts incorporating both thick and thin sections with less shrink-age andwarpage and with a better surface finish, but with a shorter cycle time. The water-assisted injection molding process can also enable greater freedom of design, material savings, weight reduction, and cost savings in terms of tooling and press capacity requirements [2–4]. Typical applications include rods and tubes, and large sheet-like structural parts with a built-in water channel network. On the other hand, despite the advantages associated with the process,the molding window and process control are more critical and difficult since additional processing parameters are involved. Water may also corrode the steel mold, and some materials including thermoplastic composites are difficult to mold successfully. The removal of water after molding is also a challenge for this novel technology. Table 1 lists the advantages and limitations of water-assisted injection molding technology.Fig. 1. Schematic diagram of water-assisted injection molding process.Water assisted injection molding has advantages over its better known competitor process, gas assisted injection molding [5], because it incorporates a shorter cycle time to successfully mold a part due to the higher cooling capacity of water during the molding process. The incompressibility,low cost, and ease of recycling the water makes it an ideal medium for the process. Since water does not dissolve and diffuse into the polymer melts during the molding process, the internal foaming phenomenon [6] that usually occurs in gas-assisted injection molded parts can be eliminated.In addition, water assisted injection molding provides a better capability of molding larger parts with a small residual wall thickness. Table 2 lists a comparison of water and gas assisted injection molding.With increasing demands for materials with improved performance, which may be characterized by the criteria of lower weight, higher strength, and a faster and cheaper production cycle time, the engineering of plastics is a process that cannot be ignored. These plastics include thermoplastic and thermoset polymers. In general, thermoplastic polymers have an advantage over thermoset polymers in popular materials in structural applications.Poly-butylene-terephthalate (PBT) is one of the most frequently used engineering thermoplastic materials, whichis formed by polymerizing 1.4 butylene glycol and DMT together. Fiber-reinforced composite materials have been adapted to improve the mechanical properties of neat plastic materials. Today, short glass fiber reinforced PBT is widely used in electronic, communication and automobile applications. Therefore, the investigation of the processing of fiber-reinforced PBT is becoming increasingly important[7–10].Thisreport was made to experimentally study the waterassisted injection molding process of poly-butylene-terephthalate (PBT) materials. Experiments were carried out on an 80-ton injection-molding machine equipped with a lab scale water injection system, which included a water pump, a pressure accumulator, a water injection pin, a water tank equipped with a temperature regulator, and a control circuit. The materials included a virgin PBT and a 15% glass fiber filled PBT composite, and a plate cavity with a rib across center was used. Various processing variables were examined in terms of their influence on the length of water penetration in molded parts, which included melt temperature, mold temperature, melt filling speed, short-shot size, water pressure, water temperature,water hold and water injection delay time. Mechanical property tests were also performed on these molded parts,and XRD was used to identify the material and structural parameters. Finally, a comparison was made betweenwater-assisted and gas-assisted injection molded parts.Table 12. Experimental procedure2.1. MaterialsThe materials used included a virgin PBT (Grade 1111FB, Nan-Ya Plastic, Taiwan) and a 15% glass fiber filled PBT composite (Grade 1210G3, Nan-Ya Plastic, Taiwan).Table 3 lists the characteristics of the composite materials.2.2. Water injection unitA lab scale water injection unit, which included a water pump, a pressure accumulator, a water injection pin, a water tank equipped with a temperature regulator, and a control circuit, was used for all experiments [3]. An orifice-type water injection pin with two orifices (0.3 mm in diameter) on the sides was used to mold the parts. During the experiments, the control circuit of the water injection unit received a signal from the molding machine and controlled the time and pressure of the injected water. Before injection into the mold cavity, the water was stored in a tank with a temperature regulator for 30 min to sustain an isothermal water temperature.2.3. Molding machine and moldsWater-assisted injection molding experiments were conducted on an 80-tonconventional injection-molding machine with a highest injection rate of 109 cm3/s. A plate cavity with a trapezoidal water channel across the center was used in this study. Fig. 2 shows the dimensions ofthe cavity. The temperature of the mold was regulated by a water-circulating mold temperature control unit. Various processing variables were examined in terms of their influence on the length of water penetration in water channels of molded parts: melt temperature, mold temperature, meltfill pressure, water temperature and pressure, water injection delay time and hold time, and short shot size of the polymer melt. Table 4 lists these processing variables as well as the values used in the experiments.2.4. Gas injection unitIn order to make a comparison of water and gas-assisted injection molded parts, a commercially available gas injection unit (Gas Injection PPC-1000) was used for the gas assisted injection molding experiments. Details of the gas injection unit setup can be found in the Refs. [11–15].The processing conditions used for gas-assisted injection molding were the same as that of water-assisted injection molding (terms in bold in Table 4), with the exception of gas temperature which was set at 25 C.2.5. XRDIn order to analyze the crystal structure within the water-assisted injection-molded parts, wide-angle X-ray diffraction (XRD) with 2D detector analyses in transmission mode were performed with Cu Ka radiation at 40 kV and 40 mA. More specifically, the measurements were performed on the mold-side and water-side layers of the water-assisted injection-molded parts, with the 2h angle ranging from 7 to 40 . The samples required for these analyses were taken from the center portion of these molded parts. To obtain the desired thickness for the XRD samples, the excess was removed by polishing theTable 3samples on a rotating wheel on a rotating wheel, first with wet silicon carbide papers, then with 300-grade silicon carbide paper, followed by 600- and 1200-grade paper fora better surface smoothness.2.6. Mechanical propertiesTensile strength and bending strength were measured on a tensile tester. Tensiletests were performed on specimens obtained from the water-assisted injection molded parts (see Fig. 3) to evaluate the effect of water temperature on the tensile properties. The dimensions of specimens forthe experiments were 30 mm · 10 mm · 1 mm. Tensile tests were performed in a LLOYD tensiometer according to the ASTM D638M test. A 2.5 kN load cell was used and the crosshead speed was 50 mm/min.Bending tests were also performed at room temperature on water-assisted injection molded parts. The bending specimens were obtained with a die cutter from parts (Fig. 3) subjected to various water temperatures.The dimensions of the specimens were 20 mm · 10 mm · 1 mm. Bending tests were performed in a micro tensile tester according to the ASTM D256 test. A 200 N load cell was used and the crosshead speed was 50 mm/min.2.7. Microscopic observationThe fiber orientation in molded specimens was observed under a scanning electron microscope (Jeol Model 5410).Specimens for observation were cut from parts molded by water-assisted injection molding across the thickness (Fig. 3). They were observed on the cross-section perpendicular to the flow direction. All specimen surfaces were gold sputtered before observation.3. Results and discussionAll experiments were conducted on an 80-ton conventional injection-molding machine, with a highest injection rate of 109 cm3/s. A plate cavity with a trapezoidal water channel across the center was used for all experimentsTable 4Fig. 3. Schematically, the positioning of the samples cut from the molded parts for tensile and bending tests and microscopic observations.3.1. Fingerings in molded partsAll molded parts exhibited the water fingering phenomenon at the channel to plate transition areas. In addition,molded glass fiber filled composites showed more severe water fingerings than those of non-filled materials, as shown photographically in Fig. 4. Fingerings usually form when a less dense, less viscous fluid penetrates a denser,more viscous fluid immiscible with it. Consider a sharp two phase interface or zone where density and viscosity change rapidly. The pressure force (P2 P1) on the displaced fluid as a result of a virtual displacement dx of the interface can be described by [16], where U is the characteristic velocity and K is the permeability.If the net pressure force is positive, then any small displacement will be amplified and lead to an instabilityand part fingerings. For the displacement of a dense, viscous fluid (the polymer melt) by a lighter, less viscous one (water), we can have Dl = l1 l2 > 0, and U > 0 [16].In this case, instability and the relevant fingering result when a more viscous fluid is displaced by a less viscous one, since the less viscous fluid has the greater mobility.The results in this study suggest that glass fiber filled composites exhibit a higher tendency for part fingerings. This might be due to the fact that the viscosity difference Dl between water and the filled composites is larger than the difference between water and the non-filled materials. Waterassisted injection molded composites thus exhibit more severe part fingerings.Fig. 4. Photograph of water-assisted injection molded PBT composite part.3.2. Effects of processing parameters on water penetrationVarious processing variables were studied in terms of their influence on the water penetration behavior. Table 4 lists these processing variables as well as the values used in the experiments. To mold the parts, one central processing condition was chosen as a reference (bold term in TableBy changing one of the parameters in each test, we were able to better understand the effect of each parameter on the water penetration behavior of water assisted injection molded composites. After molding, the length of water penetration was measured. Figs. 5–10 show the effects of these processing parameters on the length of water penetration in molded parts, including melt fill pressure, melt temperature, mold temperature, short shot size, water temperature, and water pressure.The experimental results in this study suggest that water penetrates further in virgin PBT than in glass fiber filled PBT composites. This is due to the fact that with the reinforcing glass fibers the composite materials have less volumetric shrinkage during the cooling process. Therefore,they mold parts with a shorter water penetration length.The length of water penetration decreases with the melt fill pressure (Fig. 5). This can be explained by the fact that increasing the melt fill pressure increases the flow resistance inside the mold cavity. It is then more difficult for the water to penetrate into the core of the materials. The length of water penetration decreases accordingly [3].The melt temperature was also found to reduce the water penetration in molded PBT composite parts (Fig. 6). This might be due to the fact that increasing the melt temperature decreases viscosity of the polymer melt.A lower viscosity of the materials helps the water to packthe water channel and increase its void area, instead of penetrating further into the parts [4]. The hollow core ratio at the beginning of the water channel increases and the length of water penetration may thus decrease.Increasing the mold temperature decreases somewhat the length of water penetration in molded parts (Fig. 7).This is due to the fact that increasing the mold temperature decreases the cooling rate as well as the viscosity of the materials. The water then packs the channel and increases its void area near the beginning of the water channel,instead of penetrating further into the parts [3]. Molded parts thus have a shorter water penetration length.Increasing the short shot size decreases the length of water penetration (Fig. 8). In water-assisted injection molding, the mold cavity is partially filled with the polymer melt followed by the injection of water into the core of the polymer melt [4]. Increasing the short shot size of the polymer melt will therefore decrease the length of water penetration in molded parts.For the processing parameters used in the experiments,increasing the water temperature (Fig. 9) or the water pressure(Fig. 10) increases the length of water penetration in molded parts. Increasing the water temperature decreases the cooling rate of the materials and keeps the polymer melt hot for a longer time; the viscosity of the materials decreases accordingly. This will help the water penetratefurther into the core of the parts [3]. Increasing the water pressure also helps the water penetrate into the materials.The length of water penetration thus increases.Finally, thedeflection of molded parts, subjected to various processing parameters, was also measured by a profilemeter.The maximum measured deflection is considered as the part warpage. The result in Fig. 11 suggests that the part warpage decreases with the length of water penetration.This is due to the fact that the longer the water penetration,the more the water pressure can pack the polymeric materials against the mold wall. The shrinkage as well as the relevant part warpage decreases accordingly.Fig. 5. Effects of melt fill pressure on the length of water penetration in molded parts.Fig. 6. Effects of melt temperature on the length of water penetration in molded parts.Fig. 9. Effects of water temperature on the length of water penetration in moldedparts.Fig. 7. Effects of mold temperature on the length of water penetration in molded parts.Fig. 8. Effects of short shot size on the length of water penetration inmolded parts.Fig. 10. Effects of water pressure on the length of water penetration inmolded parts.3.3. Crystallinity of molded partsPBT is a semi-crystalline thermoplastic polyester with a high crystallization rate. In the water-assisted injection molding process, crystallization occurs under non-isothermal conditions in which the cooling rate varies with cooling time. Here the effects of various processing parameters(including melt temperature, mold temperature, and water temperature) on the level of crystallinity in molded parts were studied. Measurements were conducted on a wideangle X-ray diffraction (XRD) with 2D detector analyses(as described in Section 2). The measured results in Fig. 12 showed that all materials at the mold-side lay erexhibited a higher degree of crystallinity than those at the water-side layer. The result indicates that the water has a better cooling capacity than the mold during the cooling process. This matches our earlier finding [17] by measuring the in-mold temperature distribution. In addition, the experimental result in Fig. 12c also suggests that the crystallinity of the molded materials generally increases with the water temperature. This is due to the fact that increasing the water temperature decreases the cooling rate of the materials during the cooling process. Molded parts thus exhibited a higher level of crystallinity.On the other hand, to make a comparison of the crysallinity of parts molded by gas and water, gas-assisted injection molding experiments were carried out on the same injection molding machine as that used with water, but equipped with a high-pressure nitrogen gas injection unit [11–15]. The measured results in Fig. 13 suggests that gas-assisted injection molded parts have a higher degree of crystallinity than water-assisted injection mold parts.This is due to the fact that water has a higher cooling capacity and cools down the parts faster than gas. Parts molded by water thus exhibited a lower level of crystallinity than those molded by gas.Fig. 11. Measured warpage of molded parts decreases with the length of waterpenetration.3.4. Mechanical propertiesTensile tests were performed on specimens obtained from the water-assisted injection molded parts to examine the effect of water temperature on the tensile properties.Fig. 14 showed the measured decrease subjected to various water temperatures. As can be observed, both yield strength and the elongational strain at break of water assisted molded PBT materials decrease with the water temperature. On the other hand, bending tests were also performed at room temperature on water-assisted injection molded parts. The measured result in Fig. 15 suggests that the bending strength of molded parts decreases with the water temperature.Increasing the water temperature generally decreases the cooling rate and molds parts with higher level of crystallin-content of free volume and therefore an increasing level of stiffness. However, the experimental results here suggest that the quantitative contribution of crystallinity to PBT’s mechanical properties is negligible, while there is a more important quantitative increase of tensile and bending strength for the PBT materials. The mechanical properties of molded materials are dependent on both the amount and the type of crystalline regions developed during processing.The fact that the ductility of PBT decreases with the degree of crystallinity may indicate that a more crystalline and stiffer PBT developed at a lower cooling rate during processing and did not exhibit higher stress values in tensile tests because of a lack of ductility, and therefore did not behave as strong as expected from their stiffness [18]. Nevertheless,more detailed experiments will be needed for the future works to investigate the morphological parameters of water-assisted injection molded parts and their correlation with the parts’ mechanical properties.3.5. Fiber orientation in molded partsSmall specimens were cut out from the middle of molded parts in order to observe their fiber orientation. The position of the specimen for the fiber orientation observation is as shown in Fig. 3. All specimen surfaces were polished and gold sputtered before observation. Fig. 16 shows the microstructure of the water-assisted injection molded composite parts. The measured result suggests that the fiber orientation distribution in water-assisted injection molded parts is quite different from that of conventional injection ity. As is usually encountered in semi-crystalline thermoplastics,a higher degree of crystallization means a lower molded parts.Inconventional injection molded parts, two regions are usually observed: the thin skin and the core. In the skin region near the wall, all fibers are oriented parallel to the injection molding, water-assisted injection molding technology is different in the way the mold is filled. With a conventional injection molding machine, one cycle is characterized by the phases of filling, packing and cooling.In the water-assisted injection molding process, the mold cavity is partially filled with the polymer melt followed by the injection of water into the core of the polymer melt.The novel filling process influences the orientation of fibers and matrix in a part significantly.From Fig. 16, the fiber orientation in water-assisted injection molded parts can be approximately divided intothree zones. In the zone near the mold-side surface where the shear is more severe during the mold filling, fibers are principally parallel. For the zone near the water-side surface,the shear is smaller and the velocity vector greater.In this case, the fiber tends to be positioned more transversely in the direction of injection. At the core, the fibers tend to be oriented more randomly. Generally speaking,the glass fibers near the mold-side surface of molded parts were found to be oriented mostly in the flow direction, and oriented substantially perpendicular to the flow direction with increasing distance from the mold-side surface.Finally, it should be noted that a quantitative comparison of morphology and fiber orientation [21] in waterassisted molded and conventional injection molded parts will be made by our lab in future works.Fig. 16. Fiber orientation across the thickness of water-assisted injection molded PBTcomposites.4. ConclusionsThis report was made to experimentally study the water-assisted injection molding process of poly-butylene-terephthalate(PBT) composites. The following conclusions can be drawn based on the current study.1. Water-assisted injection molded PBT parts exhibit the fingering phenomenon at the channel to plate transition areas. In addition, glass fiber filled composites exhibit more severe water fingerings than those of non-filled materials.2. The experimental results in this study suggest that the length of water penetration in PBT composite materials increases with water pressure and temperature, and decreases with melt fill pressure, melt temperature, and short shot size.3. Part warpage of molded materials decreases with the length of water penetration.4. The level of crystallinity of molded parts increases with the water temperature. Parts molded by water show a lower level of crystallinity than those molded by gas.5. The glass fibers near the surface of molded PBT composite parts were found to be oriented mostly in the flow direction, and oriented substantially perpendicular to the flow direction with increasing distance from the skin surface.玻璃纤维增强复合材料水辅注塑成型的实验研究摘要：本报告的目的是通过实验研究聚对苯二甲酸丁二醇复合材料水辅注塑的成型工艺。

注射模具的介绍外文翻译、中英文翻译、外文文献翻译

The introdution of the Injection Mold1. Mold basic knowledge1.1 IntroductionThere is a close relationship with all kinds of mold,which are refered to our daily production, and life in the use of the various tools and products, the large base of the machine tool, the body shell, the first embryo to a small screws, buttons, as well as various home appliances shell. Mold’s shape determine the shape of these products, mold’s precision and machining quality determine the quality of these products,too. Because of a variety of products, appearance, specifications and the different uses,mold devide into Die Casting into the mould, die forging, die-casting mould, Die, and so on other non - plastic molds, as well as plastic mold. In recent years, with the rapid development of the plastics industry, and GM and engineering plastics in areas such as strength and accuracy of the continuous enhancement , the scope of the application of plastic products have also constantly expanded, such as: household appliances, instrumentation, construction equipment, automotive, daily hardware, and many other fields, the proportion of plastic products is rapidly increasing. A rational design of plastic parts often can replace much more traditional metal pieces. The trend of industrial products and daily products plasticed is rising day after day.1.2 Mold general definitionIn the industrial production，with the various press and the special instruments which installed in the press,it produces the required shape parts or products through pressure on the metal or non-metallic materials, this special instruments collectively call as the mold.1.3 Mold general classificationMold can be divided into plastic and non - plastic mould: (1) Non-plastic mould: Die Casting, forging Die, Die, die-casting mould and so on. A. Die Casting - taps, pig iron platformB. Forging Die - car body C. Die - computer panel D. Die Casting Die - superalloy, cylinder body (2) For the production technology and production, the plastic mold are divided into different products: A. Injection molding die - TV casing, keyboard button (the most common application) B. Inflatable module - drink bottles C. Compression molding die - bakeliteswitches, scientific Ciwan dish D. Transfer molding die - IC products E. Extrusion die - of glue, plastic bags F. Hot forming die - transparent shell molding packaging G. Rotomoulding mode - Flexible toy doll. Injection Molding is the most popurlar method in plastics producing process. The method can be applied to all parts of thermoplastic and some of thermosetting plastics, the quantity of plastic production is much more than any other forming method.Injection mold as one of the main toolsof injection molding processing,whosh production efficiency is low or high in the quality of precision、manufacturing cycle and the process of injection molding and so on,directly affect the quality of products, production, cost and product updates, at the same time it also determines the competitiveness of enterprises in the market's response capacity and speed. Injection Mold consists of a number of plate which mass with the various component parts. It divided into: A molding device (Die, punch)B positioning system (I. column I. sets) C fixtures (the word board, code-pit) D cooling system (carrying water hole) E thermostat system (heating tubes, the hotline) F-Road System (jack Tsui hole, flow slot, streaming Road Hole) G ejection system (Dingzhen, top stick).1.4 Type of moldIt can be divided into three categories according to gating system with the different type of mold :(1) intake die: Runner and gate at the partig line,it will strip together with products when in the open mode,it is the most simple of design, easy processing and lower costing.So more people operations by using large intake system. (2) small inlet die:It general stay in the products directly,but runner and gate are not at the partig line.Therefore,it should be design a multi-outlet parting line.And then it is more complex in the designing, more difficult in processing, generally chosing the small inlet die is depending on the product’s requirements. (3) hot runner die:It consists of heat gate, heat runner plate, temperature control box. Hot runner molds are two plate molds with a heated runner system inside one half of the mold. A hot runner system is divided into two parts: the manifold and the drops. The manifold has channels that convey the plastic on a single plane, parallel to the parting line, to a point above the cavity. The drops, situated perpendicular to the manifold, convey the plastic from the manifold to the part. The advantages of hot runner system ：(1)No outlet expected, no need processing, the whole process fully automated, save time and enhance the efficiency of the work. (2) small pressure loss.2、Injection MoldThere are many rules for designing molds.These rules and standard practices are based on logic,past experience,convenience,and economy.For designing,mold making,and molding,it is usually of advantage to follow the rules.But occasionally,it may work out better if a rule is ignored and an alternative way is selected.In some texts,the most common rules are noted,but the designer will learn only from experience which way to go.The designer must ever be open to new ideas and methods,to new molding and mold material that may affect these rules.The process consists of feeding a plastic compound in powdered or granular form from a hopper through metering and melting stages and then injecting it into a mold.Injection molding process: Mold is a production of plastic tool. It consists of several parts and this group contains forming cavities. When it injects molding, mold clamping in the injection molding machine, melting plastic is Injected forming cavities and cooling stereotypes in it, then it separate upper and lower die,it will push the production from the cavity in order to leave the mold through ejection system, finally mold close again and prepared the next injection. The entire process of injection is carried out of the cycle.An injection mold consists of at least two halves that are fastened to the two platens of the injection molding machine so that can be opened and closed.In the closed position,the product-forming surfaces of the two mold halves define the mold cavity into which the plastic melt is injected via the runner system and the gate.Cooling provisions in the mold provide for cooling and solidification of the molded product so that it can be subsequently ejected.For product ejection to occur,the mold must open.The shape of the molded product determines whether it can be ejected simply by opening the two mold halves or whether undercuts must be present.The design of a mold is dictated primarily by the shape of the product to be molded and the provisions necessary for product ejection.Injection-molded products can be classified as:1).Products without undercuts.2).products with external undercuts of lateral openings.3).products with internal undercuts.4).products with external and internal undercuts.3.The composition of injection mold3.1 Mold Cavity SpaceThe mold cavity space is a shape inside the mold,when the molding material is forced into this space it will take on the shape of the cavity space.In injection molding the plastic is injected into the cavity space with high pressure,so the mold must be strong enough to resist the injection pressure without deforming.3.2 Number of CavitiesMany molds,particularly molds for larger products,ate built for only 1 cavity space,but many molds,especially large production molds,are built with 2 or more cavities.The reason for this is purely economical.It takes only little more time to inject several cavities than to inject one.Today,most multicavity molds are built with a preferred number ofcavities:2,4,6,8,12,16,24,32,48,64,96,128.These numbers are selected because the cavities can be easily arranged in a rectangular pattern,which is easier for designing and dimensioning,for manufacturing,and for symmetry around the center of the machine ,which is highly desirable to ensure equal clamping force for each cavity.3.3 Cavity and CoreBy convention,the hollow portion of the cavity space is called the cavity.The matching,often raised portion of the cavity space is called the core.Most plastic products are cup-shaped.This does not mean that they look like a cup,but they do have an inside and an outside.The outside of the product is formed by the cavity, the inside by the ually,the cavities are placed in the mold half that is mounted on the injection side,while the cores are placed in the moving half of the mold.The reason for this is that all injection molding machines provide an ejection mechanism on the moving platen and the products tend to shrink onto and cling to the core,from where they are then ejected.Most injection molding machines do not provide ejection mechanisms on the injection side.For moulds containing intricate impressions,and for multi-impression moulds, it is not satisfactory to attempt to machine the cavity and core plates from single blocks of steel as with integer moulds. The cavity and core give the molding its external and internal shapes respectively, the impression imparting the whole of the form to the molding.3.4 The Parting LineTo be able to produce a mold,we must have ta least two separate mold halves,with the cavity in one side and the core in the other.The separation between these plates is called the parting line,and designated P/L.Actually,this is a parting area or plane,but,by cinvention,in this intext it is referred to as a line. The parting surfaces of a mould are those portion of both mould plates, adjacent to the impressions, which butt together to form a seal and prevent the loss of plastic material from the impression.The parting line can have any shape, many moldings are required which have a parting line which lies on a non-planar or curved surface,but for ease of mold manufacturing,it is preferable to have it in one plane.The parting line is always at the widest circumference of the product,to make ejection of the product from the mold possible.With some shapes it may be necessary to offset the P/L,or to have it at an angle,but in any event it is best to have is so that itan be easily machined,and often ground, to ensure that it shuts off tightly when the mold is clamped during injection.If the parting line is poorly finished the plastic will escape,which shows up on the product as an unsightly sharp projection,which must then be removed;otherwise,the product could be unusable.There is even a danger that the plastic could squirt out of the mold and do personal danger.3.5 Runners and GatesNow,we must add provisions for bringing the plastic into these cavity spaces.This must be done with enough pressure so that the cavity spaces are filled completely before the plastic "freezes"(that is,cools so much that the plastic cannot flow anymore).The flow passages are the sprue,from wherethe machine nozzle contactss the mold,the runners,which distribute the plastic to the individual cavities, the wall of the runner channel must be smooth to prevent any restriction to flow. Also, as the runner has to be removed with the molding, there must be no machine marks left which would tend to retain the runner in the mould plate.And the gates which are small openings leading from the runner into the cavity space. The gate is a channel or orifice connecting the runner with the impression. It has a small cross-sectional area when compared with the rest of the feed system. The gate freezes soon after the impression is filled so that the injection plunger can be withdrawn without the probability of void being created in the molding by suck-back.4. The injection molding machine processInjection Mold is installed in the injection molding machine, and its injection molding process is completed by the injection molding machine. Following is the injection molding machine process.The molding machine uses a vacuum to move the plastic from the dryer to it's initial holding chamber. This chamber is actually a small hopper on the back of the "barrel" of the machine。

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二、The injection and Compression MoldingInjection molding si principally used for the production of the thermoplastic parts, although some progress has been made in developing a method for injection molding some thermosetting materials. The problem of injecting a melted plastic into a mold cavity form a reservoir of melted material has been extremely difficult to solve for thermosetting plastics which cure and harden under such conditions within a few minutes. The principle of injection molding is quite similar to that of die-casting. The process consists of feeding a plastic compound in powdered or granular form from a hopper through metering and melting stages and then injecting it into a mold. After a brief coolling period, the mold is opened and the solidified part ejected. Injection-molding machines can be arranged for manual operation, automatic single-cucle operation, and full automatic operation. The advantage of injection molding are:(i) a high molding speed adapted for mass production is possible;(ii)there is a wide choice of thermoplastic materials providinga variety of usefull properties;(iii)it is possible to mold threads, undercuts, side holes, and large thin sections.Several methods are used to force or inject the melted plastic into the mold. The most commonly used system in the larger machines is the in-line reciprocating screw.The screw acts as a combination and plasticizing unit.As the plastic is fed to the rotating screw,it passes through three zones as shown: feed,compression, and metering. After the feed zone, the screw-flight depth is gradually reduced,forcing the plastic to compress. The work is converted to heat by shearing the plastic, making it a semifluid mass. In the metering zone, additional heat is applied by conduction from the barrel surface. As the chamber in front of the screw becomes filled, it forces the screw back, tripping a limit switch that activates a hydraulic cylinder that forces the screw forwardand injects the fluid plastic into the closed mold.An antiflowback valve prevents plastic under pressure from escaping back into the screw flights.The clamping force that a machine is capable of exerting is part of the size designation and is measured in tons. A rule-of-thumb can be used to determine the tonnage required for a particular job. It is based on two tons of clamp force per square inch of projected area. If the flow pattern is difficult and the parts are thin,this may have to go to three or four tons.Many reciprocating - screw machines are capable of handing thermosetting plastic materials.Previously these materials were handled by compression or transfer molding.Thermosetting materials cure or polymerize in the mold and are ejected hot in the range of 375℃～410℃.Thermoplastic parts must be allowed to cool in the mold in order to remove them without distortion.Thus thermosetting cycles can be faster.Of course the mold must be heated rather than chilled,as with thermoplastics.The importance of Injecting the mold are :⑴、Plastics have the density small, the quality light, the specifictenacity big, the insulating property good, the dielectric loss low, the chemical stability strong, the formation productivity high and the price inexpensive and so on the merits, obtained day by day the widespread application in the national economy and people's daily life each domain, as early as in the beginning of 1990s, the plastic annual output already surpassed the steel and iron and the non-ferrous metal annual output sum total according to the volume computation.In mechanical and electrical (for example so-called black electrical appliances), domains and so on measuring appliance, chemical, the automobile and astronautics aviation, the plastic has become the metal the good substitution material, had the metal material plastic tendency.⑵、Take the automobile industry as the example , as a result of theautomobile lightweight, the low energy consumption development request, the automobile spare part material constitution occurred obviously has modelled the band steel the change, at present our country automobile plastic accounts for 5% which the automobile was self-possessed to 6%, but overseas has reached 13%, forecast according to the expert, the automobile plastic bicycle amount used will also be able further to increase.On modern vehicles, regardless of is outside installs the assorted items, the internal installation assorted items, the function and the structural element, all may use the plastic material, outside installs the assorted items to have the bumper, the fender, the wheel hub cap, the air deflector and so on;After the internal installation assorted items have in the display board, the vehicle door the board, the vice-display board, the sundry goods box lid, the chair, the guard shield and so on; The function and the structural element have the fuel tank, the radiator header, the spatial filter hood, the fan blade and so on.Statistics have indicated, our country in 2000 automobile output more than 200 ten thousand, the vehicle amounted to 1,380,000 tons with the plastic.Looked from the domestic and foreign automobile plastic application situation that, the automobile plastic amount used already became one of weight automobile production technical level symbols.⑶、Injection of a molding formation as plastic workpiece most effectiveformation methods because may by one time take shape each kind of structure complex, the size precise and has the metal to inlay a product, and the formation cycle is short, may by mold multi-cavities, the productivity be high, when mass productions the cost isvery inexpensive, easy to realize the automated production, therefore holds the extremely important status in the plastic processing profession.Statistics have indicated, plastic mold composition all molds (including metal pattern) 38.2%, the plastic product grossweight about 32% is uses in injecting the formation, 80% above engineering plastics product all must use the injection formation way production. 4. counts according to the customs, our country in 2000 altogether imported mold 977,000,000 US dollars, in which plastic molding forms altogether 550,000,000 US dollars, occupied for56.3%,2001 years altogether to import mold 1,112,000,000 US dollars,in which plastic molding forms altogether 616,000,000 US dollars, accounted for 55.4%.From the variety, the import volume biggest is the plastic molding forms.⑷、Counts according to the customs, our country in 2000 altogetherimported mold 977,000,000 US dollars, in which plastic molding forms altogether 550,000,000 US dollars, occupied for 56.3%, 2001 years altogether to import mold 1,112,000,000 US dollars, in which plastic molding forms altogether 616,000,000 US dollars, accounted for55.4%.From the variety, the import volume biggest is the plasticmolding forms.In compression molding the palstic material as powder or preforms is placed into a heated steel mold cavity,Since the parting surface is in a horizontal plane ,the upper half of the mold descends vertically.It closes the mold cavity and pressures for a predetermined period.A pressure of from 2 to 3 tons square inch and a temperaure at approximately 350F converts the plastic to a semiliquid which flows to all parts of the mold ually from 1 to 15 minutes is required for curing,altough a recently developed alkyd plastic will cure in less than 25 secends. The mold is then opended and the molded part removed.If metal insers are desired in the parts,they should be placed in the mold cavity on pins or in the holes before the plastic is loaded.Also, the preforms should be preheated before loading into the mold cavity to eliminate gases,inprove flow,and decrease curing time.Dieletric heating is a convenient method of heating the preforms.Since the plastic material is placed directly into the mold cavity,the mold itself can be simpler than those used for other molding precesses.Gates and sprues are unnecessary.This also results in a saving in material,because trimmed-off gates and sprues would be a complete loss of the thermosetting plastic.The press require the full attention of one operator.However,several smaller presses can be operated by one operator. The presses are conveniently located so the operator can easilymove from one to the next.By the time he gets around to a particular press again,that mold will be ready to open.the thermosetting plastics which harden under heat and pressure are suitable for compression molding and transfer molding.It is not practical to moid shermoplastic materials by these methods,since the molds would have to be alternately heated and cooled.In order to harden and eject thermoplastic parts form the mold,cooling would be necessary.Types of molds for compression molding.The molds used for compression molding are classified into four basic types, namely ,positive molds,landed positive mold,flash-type molds,and semipositive molds.In a positive mold the plunger on the upper mold enters the lower mold cavity.since there are no lands or stops on the lower die ,the plunger completely trap the plastic material and descends with full pressure on the charge.A dense part with good electrical and physical properties is produced.The amount of plastic placed in the die cavity must be accurately measured,since it determines the thickness of the part .A landed positive mold is similar to a positive mold except that lands are added to stop the travel of the plunger at predetermined point.In this case,the lands absorb some of the pressure that should be exerted on the parts.The thickness of the parts will be accurately controlled,but the density may vary cansideraby.In a flash-type mold,flash redges are added ti the top and bottom molds.As the upper mold exerts pressure on the plastic,excess material is forced out between the flash ridges where it forms flash.This flash is further compressed.becomes hardened,and finally stops thedownard thavel of the upper mold.A slight excess of the plastic material is always chared to ensure sufficient pressurs to produce a dense molded part.This type of mold is widely used because it is comparatively easy to construct and it controls thickness and density within colse limits.The semipositive mold is a combination od the flash type and landed posive molds.In addition to the flash ridges,a land is employed to restrict the travel of the upper mold.二、注塑模和压缩模尽管成型某些热固性材料的方法取得了一定进步，但注塑模主要（还是）用来生产热塑性塑件（这主要是因为）热固性塑料熔体的过程中，也会出现这种情况，这个问题一直非常难解决。