压铸模类外文翻译——压塑和压铸工艺

压塑和压铸工艺近年，压塑工艺应用于热固性掺混料，如脲醛塑料、酚醛树脂、环氧树脂、蜜胺树脂和橡胶中。

尽管有一些材料可注射成型，但采用压塑工艺仍非常普遍。

压铸用材料较压塑用材料要求可塑性更软。

许多热固性材料具有高抗冲级（1.0ft一lb）和良好缺口冲击强度的保持性，只有在极限压力下才会流动。

压塑热固性材料的压塑成型的明显优点是系统简单。

将材料置入一加热型腔，保压至所要求团化时间。

因工艺过程简单，费用少。

添加剂和增强剂无规则，并能得到较好强度。

由于无浇口和流道，不浪费材料，模具几乎也不用维修。

零件的统一性好，无铸口和流痕，减少了修饰成本。

根据制品结构和所用的塑料应用特点，可采用全压式模具、半压式模具和闭模（可参见有关压塑模具方面的文章）。

设备：简单也是压塑设备的主要特点。

两半压板结合在一起，加温，加压，将材料制成预定形状。

多数压塑过程采用液压操作；也有采用气动操作的。

上下两压板在压力之下在4个角柱上上下移动。

根据压塑设备的大小，压力一般为20—1000吨。

压板的大小一般为8英寸2到5英尺2.在加料和固化以后的脱模方面存在不同自动化程度，常用最现代的液压机进行。

以前的简单系统有温度控制、压力控制、停压控制和时间控制。

现代设备采用更高级的微处理机控制。

对于较薄的制品，在板中可用加热筒或带式加热器。

对较深的制件，需要用筒形电加热器、蒸汽加热或热油系统加热。

有数种用于压塑中的加热体系：用蒸汽加热模温均匀，但加热温度限在350°F以下；套筒加热或其它加热（加热盘管、加热带等）比较干净，易于保养，用得比较普及；热油加热，由于加热介质循环稳定，所以加热均匀。

现在又有许多新加热方法，热水加热，类似于热油加热，加热介质一水一气体燃烧连续循环，可提供更高的压塑温度。

增强改性高分子材料工业发展迅速，要求压塑工业有新改进。

模塑增强塑料用两个模具：阳模（模塞）和阴模（模腔）。

当模具充满增强材料时，对模的两半热模具闭合，然后加热、加压固化得到产品。

相配合的模具复杂性变化很大，可用铝、塑料或钢制做。

轻质材料制做起来比较便宜，一般用于短期生产如“冷模塑”。

冷模塑用室温固化树脂，但仍使用模具和压塑液压机。

长期生产用硬化钢模具比较合算，对截坯口可提供较好的剪切性能和优良的光洁度。

这些压塑钢模采用机械上适配的截坯口，通常面对合模区。

用这种对模的金属模具，其制品表面均匀，光洁度好。

闭模工艺用于压塑成型、压铸成型、注射成型及一些可冲压的增强复合材料。

一些热塑材塑料可压塑模塑，但一般还是用预掺混的热固性树脂如BMC（预制整体模塑料）、SMC（片料成型模塑料）、TMC（厚模塑料）、毡片成型等。

毡片成型有时叫湿成型复合材料，在液压机的作用下将增强材料和树脂结合在一起。

经常在模中放置毡片，将树脂倾倒在加强材料上。

在加压过程中树脂充满模腔时加强材料固定不动。

若制件有严重的异形或斜度，有必要进行预成型。

多数毡片和预成型制州在投影面积上需要加150—200磅／英寸2的模压力。

预掺混料，如SMC，预浸树脂，填料、催化剂和增强料切割成一定大小队片状，再加入热的模具中（一般300—400°F），在1000～2000磅／英寸2压力下模塑。

用于SMC的较新的压塑设备的总循环周期可少于一分钟（从头到尾）。

已经发展了用特殊的液压装置推回压塑机中料筒，自动控制压板的水平度。

增强塑料，如SMC，用金属对模压塑光洁度好，这对制件的表面很重要。

在加工时有时出现纤维状的收缩。

用内模涂层的方法可改进表面光洁度。

BMC的压塑过程是最老的预掺混后的模塑过程之一。

填料（木屑、矿物料、纤维素等）的掺混混合是在叶片形的混合器中进行的。

将一批料装入300～400°F的模具中．在500磅／英寸2压力下模塑。

因用料廉价，所以原料成本低。

不过由于在模塑过程中纤维的定向性降低了机械强度。

高速压塑，即增强热塑性塑料片材的冲压，用途广泛。

玻璃毡片和聚丙烯相配合用于可冲压的塑料，其循环周期低于40秒。

生坯送至对流炉中加热。

加热以后，毛坯放入压塑模具中，这一过程用新的压塑机速度可达1400英寸／分钟。

以75英寸／分钟（比SMC的压塑过程快约3倍）加压进料。

根据市场的要求，有些新的可冲压塑料，表面光洁度好，并且具有可涂布性。

模塑压力一般1吨／英寸2。

传统的压塑工艺近几年一直呈增长的趋势。

在空间技术和国防方面的应用正在使这种工艺向其难点冲击。

在SMC、BMC、TMC、热塑性片材的冲压、增强材料的掺混和压塑机械方面的发展迅速增长，以适应工业的新要求。

一些先进的掺混料的压塑主要是在空间技术和国防应用方面发展迅速。

工具和模具的新概念及高温（达1200°F）模塑机，使石墨一碳纤维复合材料得以发展，代替了现有的金属铸件。

高温硅树脂正用作高压介质。

复合材料做的片层用于压塑模中。

现在，材料和生产成本已使该工艺更加适于空间技术市场，这类硅树脂也很快转向汽车领域。

压铸在压铸工艺中，热固性树脂料加入一单独的料腔，常叫料槽，然后强制送入一个或多个闭模中进行聚合（固化）。

料道，也叫注道和流道，使物料从料槽流向模腔，进入模腔之前经过限流器或浇口。

很多模腔具有单一料槽。

料腔中的空气被进来的物料所置换，并通过一特别放置的排气口排出。

当物料置入料槽中时，在一紧凑的测量装置中测料量，然后预热到接近聚合温度。

一次只加入足够一次的注塑量。

将预热的原料送出料槽的力再将其送往一注料器，该注料器紧接装在料槽上，以防止从活塞和料槽边之间的缝隙中漏料。

通常将密封套卡进注料器以进一步防漏。

料槽、注料器、浇口、流道和模腔的表面维持可使原料迅速固化的一定温度，根据物料性质、模具的设计和制件的几何形状该温度为280～380°F。

在压铸物达到固化期的终点时，将该次完整的压铸物进行脱模，包括脱除浇口、流道、注道和料槽中形成固化料垫（叫做残料）。

在压铸中，物料的预热很重要。

冷料流动缓慢，先进入模腔的料尚未到其终点，即可能聚合。

若发生上述情况，产品质量低劣，不仅是外观，也体现于机械性能。

有些例外，如一次注射量很少，或一些低粘度的物料。

可用加热灯或炉子加热，但有效而常用的方法是用专为塑料模塑制做的介电加热器。

Plastic and pressure die casting processIn recent years, the pressure technique used in thermosetting plastic material mixing ,such as urea-formaldehyde plastics, phenolic resin, epoxy rsin, melamine resin and rubber. In spite of some of the material can be injection moiding, but the use of plastic pressure process is still very common. More pressure die casting material used plastic materials require more malleable soft. Many thermosetting materials with high impact level (1.0ft-1b) and good impact strength of maintaining the gap, only under ertreme pressure will flow.Thermosetting plastic molding material pressure of the obvious advantages of the system is simple. Materials will be placed in a heating cavity, the pressure required by the Mission to time. As a result of the process simple, cost less. Enhancer and additive-free rules, and be able to get a better strength. As the gate and no runner ,not a waste of materials, die almost no maintenance. Parts of unity, and I cast no trace flow and reduce the cost of the modification. According to the structure and products used in the application of the characteristics of can be full-pressure die ,and die-pressure semi-closed mode (can be found in the plastic, plastic mold pressure related articles).Equipment: The pressure is a simple plastic deices the main features . platen combination of the two and a half , heating, pressure, the shape of the target material. Most of the process of plastic used hydraulic pressure to operate; also used pneumatic operation .Tow board up and down under pressure in the 4 corner posts on moving up and down. According to the plastic device the size of the pressure, the pressure is generally 20-1000 tons. The general board for the 8-inch size 2-5 feet 2.In addition, and after curing the release of different aspects of the degree of automation, the most commonly used modern hydraulic machine. Theprevious system , there is a simple temperature control, pressure control, pressure control and stop-time control. The use of modern equipment, advanced microprocessor control. For thinner products, in the board can be used in heating tube or belt heater. To the deeper parts, the need to use tube-shaped electric heater , heating steam or hot oil heating system. There are several types of plastic used in pressure in the heating system: uniform temperature steam heating mode, but the heating temperature is limited to below 350F;sleeve heating or other heating (heating coil, heating,ect.) relatively clean and easy maintenance, A more universal; thermal heating oil, heating due to the stability of the media cycle, the heat evenly. Now there are many new methods of heating ,hot water heating ,similar to the hot oil heating , water heating a medium for a gas combustion cycle , provides a greater degree of pressure temperature plastic.Polymer modified to enhance rapid industrial development requires a new pressure to improve the plastic industry . Enhanced by two molded plastic mold: mold-yang (side mode) and the negative mold (cavity). When the mold is full of reinforcements, the mode of the hot mold closed two and a half, and then heated, pressurized product to be cured. Along the lines of big changes in the complexity of the mold can be used aluminum, plastic or steel do.Light-weight materials making them less expensive, generally used for the production of short-term such as “cold-molding”.Coll at room temperature with molded resin, but the use of plastic mold and hydraulic pressure. The production of long-term use of hardened steel molds relatively cost-effective, the cut-off billet I can provide better performance and excellent cut finish. These steel pressure module on the use of machinery on the cut-off billet adapter I usually die together in the face area. This mode f metal molds, the products of its uniform surface, a good finish. Closed-mode technology used to pressure plastic molding,die-casting molding, injection and stamping some of the reinforced composites.Some of the thermoplastic plastic materials can be molded plasticpressure, but in general or with pre-mixing of thermosetting resins such as BMC (prefabricated molding as a whole),SMC(film forming material molding),TMC(thick molding),film forming, such as carpet.Carpet wet film forming sometimes called composite molding, in the hydraulic press will strengthen the role of materials and combined with resin. Often placed in the mold in carpet film will be dumped in to strengthen the resin material. Pressure in the process of cavity filled with resin to strengthen the material when fixed.If there are serious parts of the alien or gradient, it is necessary to carry out pre-forming. Most of the film and felt pre-forming system in the projected area of the state’s need to 150-200 pounds/2 inch of mold pressure. Pre-mixing materials, such as SMC, prepreg resin, filler, and the catalyst size enhance the material cut into a certain team sheet, and then adding the hot mold (in general 300-400 F), 1000-2000 1b/2 inch pressure Under the molding.SMC for the relatively new plastic devices the pressure of the total cycle may be less than one minute (from start to finish). Has developed a special hydraulic device back in the bowl pressure machine, automatic control of the board level degrees.Reinforced plastics, such as SMC, with a metal finish on molded plastic, tjis is very important parts of the surface. Sometimes occur in the processing of fibrous contraction.Model with coating method could improve the surface finish. BMC pressure of the process of plastic is the oldest pre-mixing after one of the molding process. Filling materials (wood, mineral materials, such as celluiose) are mixed in mixing the leaves in the shap of the mixer. Will feed into a group of 300~400 F in the mold. In the 500-pound/2 inches under the pressure of molding. As a result of the use of materials for low-cost, the cost of raw materials. However, as in the molding process, the orientation of fiber reduces the mechanical strength.Plastic high-speed pressure, that is, enhanced thermoplastic stampingthe sheet, a wide range of uses. Felt piece of glass and polypropylene can be used to match the plastic stamping, the cycle less than 40 seconds. Green sent to the convection heating furnace. Heating, rough pressure into plastic molds, in the process with new pressure machine machine speed up to 1400 inches/minute. To 75 inches/minute (SMC than the pressure of plastic process about 3 times as fast) feed pressure. According to the requirements of the market, some of the new stamping plastics, surface finish, and can be coated with nature. I metric ton of pressure on the general molding/2 inch. Traditional plastic pressure technology in recent years has been on the rise. In the space technology for national defense and the application of this technology is difficult to shock.In the SMC, BMC, TMC, the thermoplastic sheet stamping, reinforcement of the Blending plastic mechanical pressure and the development of the rapid growth of industry in order to meet the new requirements.A number of advanced materials mixing plastic pressure mainly in space technology and applications in the rapid development of national defense. Tools and dies and the new concept of high-temperature (up to 1200 F) molding machine to make a graphite carbon fiber composite materials can be developed to replace the existing metal castings.High temperature silicone is used as a high-pressure media. The composite sheet for the pressure in the mold. Now ,materials and production costs have made the process more suitable for space technology market, this type of silicone is also soon to the area of automobile.In the die-casting process, thermosetting resin material is expected to join a separate chamber, often called trough, and then forced into one or more closed modules for polymerization(curing).Liu, also known as Notes and the road runner, so that the flow of materials from the through cavity into the mold cavity before or after limiting gate. Many cavity with a single through. The air chamber is expected to be the replacement materials come in through a special place of the exhaust emissions.When the materials placed in the trough, in a compact measuring device detected charge, and then warm-up to close to the polymerization temperature. Only by adding a sufficient amount of time the injection.Preheat the raw materials will be sent trough of force and then a note sent to the feeder, the feeder note immediately installed in the trough, so as to prevent the pistons from the trough and gap between the edge of missing material. Taoka is usually closed to inject into the feeder to further leak-proof.Trough, the note feeder, gate, runner and mold cavity on the surface of the material can maintain the rapid solidification of a certain temperature,according to the nature of the materials, mold design and parts of the temperature of 280~380 F.In the die-casting material to reach the end of the curing period, the second-casting for a complete release, including the removal gate, runner and injecting Road in trough and the formation of curing pad material (called salvage).In the die-casting, the warm-up material is very important. Cold expected to sloe the flow, first into the cavity of the material to its destination yet, that is likely to polymerization. If it happens, poor product quality, not just the appearance, but also in mechanical properties. Some exceptions, such as injecting a small amount, or some of the low viscosity of the material. Available light or heating stove heating, but an effective and commonly used method is used for making molded plastic dielectric heater.。