塑料挤出成型毕业设计范本
塑料挤出机毕业设计范文
塑料挤出机螺杆、机筒设计初探[内容摘要]首先介绍聚氯乙烯板挤出成型生产工艺,单螺杆挤出机的工作原理、基本结构及各系统在工作中的作用,根据设计任务书要求确定挤出机的基本参数,并对挤出机主要零件螺杆和机筒进行了设计,最后对螺杆和机筒的制造要求、修复方法提出了自己的一些看法。
[关键词]挤出成型挤出机螺杆机筒设计一、PVC塑料板挤出成型工艺及主要工艺流程挤出成型是橡胶工业的基本加工工艺之一。
它是指利用挤出机及其辅机,使胶料在螺杆的推动下,连续不断地向前运动,再借助于口型挤出各种所需形状的半成品,然后由特定的辅机配合,来完成挤出成型或其他作业的工艺过程。
挤出成型工艺的优点主要是操作简单、经济,半成品质地均匀、致密,容易变换规格和断面形状,设备占地面积小,结构简单,造价低,灵活机动性大,生产能力大,且能连续操作。
(一)聚氯乙烯板挤出成型生产工艺流程及主要装置1、工艺流程塑料板的挤出成型可用聚氯乙烯﹑聚乙烯﹑聚丙烯﹑聚碳酸酯﹑ABS﹑聚偏氟乙烯和聚苯乙烯等树脂。
其生产工艺顺序如图一。
图一PVC-U异型材的生产工艺路线主要分为单螺杆挤出机成型工艺和双螺杆挤出机成型工艺。
单螺杆挤出成型工艺适用于小批量、小规格异型材生产及装饰型材生产。
其塑料板挤出机成型设备生产线如图二。
图二塑料板挤出生产线1—挤出机2—成型模具3—三辊压光机4—冷却输送辊组5—切边装置6—牵引装置7—切断机8—制品检查堆放平台2、主要装置(1)挤出成型装置挤出机与成型模具,它是制件成型的主要部件,熔融塑料通过它获得一定的几何截面和尺寸。
本设计将主要针对挤出机的工作原理进行分析研究。
(2)冷却定型装置该装置包括真空定型和水冷却两部分。
当温度为190℃左右,PVC-U熔融型坯从机头口模出口后,立即进入冷却定型模。
模内抽真空,使型材外壁和定型模具表面贴紧,并用水通过定型套进行冷却定型。
对真空吸附要求吸附力大而且均匀,定型套分型要求密封性好,特别是在筋与棱角处吸附要好,以保证型材外观和尺寸精度及表观质量。
课程设计—硬质聚氯乙烯片材挤出成型工艺设计
课程设计硬质聚氯乙烯片材挤出成型工艺设计3000t PVC片材的挤出成型工艺摘要本设计要紧介绍PVC片材的挤出成型工艺,较详细地说明了PVC片材的配方设计、挤诞生产工艺流程及参数的确信和废品的后处置等方面。
对挤出机、造粒机等型号的选定进行了明确的计算。
计算了工艺进程中物料衡算和热量衡算。
还就车间治理与生产组织、工程经济概算进行了计划。
最后确信了年产量3000t的PVC片材的挤出成型工艺,其配方设计可行,车间治理与生产组织完善.本次设计的特点是从厂区布置到车间生产进程,和废料处置最大限度的简化生产,提高生产效率,大大提高了原料的利用率,而且使污染降到最小化。
关键词:PVC,片材,挤出,配方,挤出机3000t PVC sheet extrusion molding processABSTRACTThis design introduces the PVC sheet extrusion molding process, a more detailed description of the formulation PVC sheet extrusion production process and determination of parameters and post-processing waste and so on. The extrusion machine, granulator model selected for such a clear calculation. Process of calculating the material balance and heat balance. Also on the workshop management and organization of production, engineering estimates for economic planning. Finalized the annual production of 3000t of PVC sheet extrusion molding process, the formula design is feasible, well-organized workshop management and production.This design is characterized by the production from the plant layout to the workshop process, as well as a simplified waste disposal to maximize production, improve production efficiency and greatly improved utilization of raw materials and the pollution to a minimum.KEY WORDS:PVC, sheet, extrusion, formulation, extruder目录前言 (1)第1章聚氯乙烯片材的配方设计 (3)聚氯乙烯树脂 (3). 助剂及其作用 (3)1.2.1 稳固剂 (3)填充剂 (4)润滑剂 (5)1.2.4 着色剂 (6)1.2.5 增塑剂 (7)1.2.6 阻燃剂 (7)配方 (8)第2章挤出工艺流程及参数确信 (9)成型前的预备 (9)挤出成型工艺 (10)2.2.1 挤出机的分类及选择 (10)2.2.2 挤出机的选择 (12)2.2.3 螺杆的选择 (12)2.2.3 挤出进程 (12)2.2.3 挤出装置及机头的选择 (13)2.2.4 切割装置 (13)2.2.5 冷却方式 (14)第3章物料衡算与热量衡算 (15)物料衡算 (15)物料衡算的前提及计算 (15)热量衡算 (16)第4章挤诞生产线机械数量的确信 (18)挤出机规格的确信 (18)挤出机数量的确信 (18)挤诞生产线的确信 (19)第5章废料的后处置 (20)第6章双螺杆挤出机常见故障及其处置方式 (21)第7章车间治理与生产组织 (24)治理项目 (24)生产职能形式 (25)治理及公作人员的确信 (26)第8章工程经济概算 (29)编制概算的意义 (29)编制原那么 (29)编制和修订 (29)8.3.1 设备购买费 (30)8.3.2 设备安装费 (30)概算修正 (31)总结 (34)致谢 (35)参考文献 (35)外文资料翻译 (36)前言中国在PVC硬质片材管件产业进展显现的问题中,许多情形不容乐观,如产业结构不合理、产业集中于劳动力密集型产品;技术密集型产品明显掉队于发达工业国家;生产要素决定性作用正在减弱;产业能源消耗大、产出率低、环境污染严峻、对自然资源破坏力大;企业整体规模偏小、技术创新能力薄弱、治理水平掉队等。
注塑模具设计毕业设计论文参考模板
1.前言 (3)1.1毕业设计的目的 (3)1.2题目内容及要求 (3)2.塑件的工艺分析 (3)2.1塑件材料的选择 (3)2.2塑件的工艺特性分析 (3)3.注射机的选择与模具结构形式 (3)3. 1 设备的选择与参数校核 (3)3.1.1注射机型号的选择 (3)3.1.2 模具参数的校核 (4)3.2模具结构确定 (4)3.2.1确定型腔数量及排列方式 (4)3.2.2分型面的设计 (5)4.浇注系统设计 (5)4.1浇注系统的组成 (5)4.2主流道设计 (5)4.3分流道设计 (7)4.3.1分流道的形状及尺寸 (7)4.3.2 分流道的长度 (7)4.3.3分流道的粗糙度 (7)4.4浇口的设计 (7)4.5浇注系统的平衡 (7)4.6冷料穴的设计 (7)5.成型零件的设计 (7)5.1注射成型零部件结构设计 (7)5.1.1凹模 (7)5.1.2凸模 (8)5.2成型零部件工作尺寸的计算 (8)5.2.1凹模的径向尺寸的计算 (10)5.2.2 凹模深度尺寸的计算 (11)5.2.3 凸模径向工作尺寸的计算 (11)5.2.4凸模高度工作尺寸的计算 (12)5.3成型零件的加工工艺 (12)6. 注射模导向与推出机构设计 (12)6.1导向机构的设计 (12)6.1.1导柱的结构形式 (12)6.1.2导套 (13)6.2脱模力计算 (13)6.3 推出机构的设计 (14)6.3.1推出机构的组成 (14)6.3.2推杆位置的设定 (14)6.3.3推出机构的导向 (15)6.4复位零件 (15)6.4.1复位杆复位 (16)6.4.2弹簧复位 (16)7.冷却系统的设计 (17)7.1冷却系统的设计 (17)8.1固定板 (18)8.2模脚 (18)8.3支承板与垫块 (18)9.设计总结 (18)致谢............................................................................................... 错误!未定义书签。
PS材料注塑成型工艺的研究毕业设计
(此文档为word格式,下载后您可任意编辑修改!) 渭南师范学院毕业设计设计题目聚苯乙烯注塑成型工艺的研究学生姓名魏阳____专业班级高分子材料与工程指导教师____刘展晴____2015年4月20号本论文详细介绍了聚苯乙烯(PS)塑料的注射成型技术,结合产品的模具设计,对成型工艺进行了分析讨论;通过对典型PS塑料制品的加工工艺过程的研究,对PS塑料制品生产中的缺陷、原因及解决方法进行了论述。
结果表明,PS作为通用塑料,因其具有良好的性能,在结构复杂的工艺品生产中应用效果好,而且,合理的设计可以使模具结构大大简化。
[关键词]PS 塑料;注射成型;技术;探讨1. PS 塑料成型特性分析1. 聚苯乙烯简介()聚苯乙烯(PS)是指有苯乙烯单体经自由基缩聚反应合成的聚合物,英文名称为Polystyrene,简称PS。
玻璃化温度80~90℃,非晶态密度1.04~1.06克立方厘米,晶体密度1.11~1.12克立方厘米,熔融温度240℃,电阻率为1020~1022欧·厘米[1]。
导热系数30℃时0.116瓦(米·开)。
通常的聚苯乙烯为非晶态无规聚合物,具有优良的绝热、绝缘和透明性,长期使用温度0~70℃,低温易开裂。
此外还有全同和间同立构聚苯乙烯。
普通聚苯乙烯树脂属无定形高分子聚合物,聚苯乙烯大分子链的侧基为苯环,大体积侧基为苯环的无规排列决定了聚苯乙烯的物理化学性质,如透明度高、刚度大、玻璃化温度高,性脆等。
可发性聚苯乙烯为在普通聚苯乙烯中浸渍低沸点的物理发泡剂制成,加工过程中受热发泡,专用于制作泡沫塑料产品。
高抗冲聚苯乙烯为苯乙烯和丁二烯的共聚物间规聚苯乙烯为间同结构,采用茂金属催化剂生产,是近年来发展的聚苯乙烯新品种,性能好,属于工程塑料自从20世纪30年代初期聚苯乙烯第一次在德国实现了工业生产以后,它的应用领域也在不断扩大,迄今为止,聚苯乙烯以实现了规模化、跨越式发展。
聚苯乙烯具有优越的抗水防潮性、轻质、高硬度、高抗冲性、保温性能好等特性,聚苯乙烯 (PS)是一种无色透明的热塑性树脂,PS的分子量过高,加工困难,所以通常聚苯乙烯的分子量为5~20万。
塑料挤出成型毕业设计论文
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注塑机的毕业设计
1 前言毕业设计是我们四年大学的最后一次作业,它是对我们动手能力的考查,要我们明白理论固重要,实践价更高的道理。
通过毕业设计,灵活系统的运用所学知识,提高分析,解决问题的能力。
为了把毕业设计作好,马晓录老师带领我们去了河南新飞塑料制品公司参观调研,并且自己通过到图书馆和互联网上查资料使我对注塑机有了充分直观的认识,为后续工作打下了良好的基础。
我的毕业设计项目是SJ-15型全电动注塑设备,这是一个新的项目,当前,由于我国生产水平相对较低,机械行业里国际先进水平尚有一段距离,只有很少的公司生产,大部分都是从国外引进。
但是,在老师的带领下,我们去了新飞塑料制品公司参观了一下实物,也是我意识到调研的重要性,通过对实物工作过程的感性认识,可以基本了解它的外形和工作原理,为自己的设计方案的设计奠定了基础。
通过独立完成一台机械设备的设计,使我掌握了产品设计和创新的基本方法,也懂得了机械设计的过程,增强了自己的设计能力。
调研也使我大大地开阔了眼界,增长了知识和能力,也看到了目前国内外注塑机械行业的差别,也使我增加了对注塑机械的兴趣。
通过这次的毕业设计的实习调研,使我了解到我国的注塑技术和设备是比较落后的,与国外相比有很大的差距。
只靠从国外引进技术和设备是不合理的,因为(1)、我国的国力不允许;(2)、引进的技术不能很好的消化和吸收,这对提高我国在此方面的水平是不利的。
面对我国现在的状况使得我们要努力的完成这次毕业设计,并在以后的工作中为提高我国机械制造业水平而努力。
2 概述2.1 注塑工业概述塑料工业是国民经济重要工业部门,又是一个新兴的综合性很强的工业体系。
它是由塑料制品成型及应用,塑料原料设备,塑料回收,再生与利用及相应的树脂合成设备,助剂设备,塑料准备设备,塑料成型设备,塑料二次加工设备,塑料辅助设备,机头与模具制造等组成的工业体系。
由于塑料的飞速发展,塑料制品的应用领域不断扩展,塑料加工设备已经成为国家机械工业的重要组成部分。
毕业设计论文塑料注射成型
Modeling of morphology evolution in the injection moldingprocess of thermoplastic polymersR.Pantani,I.Coccorullo,V.Speranza,G.Titomanlio* Department of Chemical and Food Engineering,University of Salerno,via Ponte don Melillo,I-84084Fisciano(Salerno),Italy Received13May2005;received in revised form30August2005;accepted12September2005AbstractA thorough analysis of the effect of operative conditions of injection molding process on the morphology distribution inside the obtained moldings is performed,with particular reference to semi-crystalline polymers.The paper is divided into two parts:in the first part,the state of the art on the subject is outlined and discussed;in the second part,an example of the characterization required for a satisfactorily understanding and description of the phenomena is presented,starting from material characterization,passing through the monitoring of the process cycle and arriving to a deep analysis of morphology distribution inside the moldings.In particular,fully characterized injection molding tests are presented using an isotactic polypropylene,previously carefully characterized as far as most of properties of interest.The effects of both injectionflow rate and mold temperature are analyzed.The resulting moldings morphology(in terms of distribution of crystallinity degree,molecular orientation and crystals structure and dimensions)are analyzed by adopting different experimental techniques(optical,electronic and atomic force microscopy,IR and WAXS analysis).Final morphological characteristics of the samples are compared with the predictions of a simulation code developed at University of Salerno for the simulation of the injection molding process.q2005Elsevier Ltd.All rights reserved.Keywords:Injection molding;Crystallization kinetics;Morphology;Modeling;Isotactic polypropyleneContents1.Introduction (1186)1.1.Morphology distribution in injection molded iPP parts:state of the art (1189)1.1.1.Modeling of the injection molding process (1190)1.1.2.Modeling of the crystallization kinetics (1190)1.1.3.Modeling of the morphology evolution (1191)1.1.4.Modeling of the effect of crystallinity on rheology (1192)1.1.5.Modeling of the molecular orientation (1193)1.1.6.Modeling of theflow-induced crystallization (1195)ments on the state of the art (1197)2.Material and characterization (1198)2.1.PVT description (1198)*Corresponding author.Tel.:C39089964152;fax:C39089964057.E-mail address:gtitomanlio@unisa.it(G.Titomanlio).2.2.Quiescent crystallization kinetics (1198)2.3.Viscosity (1199)2.4.Viscoelastic behavior (1200)3.Injection molding tests and analysis of the moldings (1200)3.1.Injection molding tests and sample preparation (1200)3.2.Microscopy (1202)3.2.1.Optical microscopy (1202)3.2.2.SEM and AFM analysis (1202)3.3.Distribution of crystallinity (1202)3.3.1.IR analysis (1202)3.3.2.X-ray analysis (1203)3.4.Distribution of molecular orientation (1203)4.Analysis of experimental results (1203)4.1.Injection molding tests (1203)4.2.Morphology distribution along thickness direction (1204)4.2.1.Optical microscopy (1204)4.2.2.SEM and AFM analysis (1204)4.3.Morphology distribution alongflow direction (1208)4.4.Distribution of crystallinity (1210)4.4.1.Distribution of crystallinity along thickness direction (1210)4.4.2.Crystallinity distribution alongflow direction (1212)4.5.Distribution of molecular orientation (1212)4.5.1.Orientation along thickness direction (1212)4.5.2.Orientation alongflow direction (1213)4.5.3.Direction of orientation (1214)5.Simulation (1214)5.1.Pressure curves (1215)5.2.Morphology distribution (1215)5.3.Molecular orientation (1216)5.3.1.Molecular orientation distribution along thickness direction (1216)5.3.2.Molecular orientation distribution alongflow direction (1216)5.3.3.Direction of orientation (1217)5.4.Crystallinity distribution (1217)6.Conclusions (1217)References (1219)1.IntroductionInjection molding is one of the most widely employed methods for manufacturing polymeric products.Three main steps are recognized in the molding:filling,packing/holding and cooling.During thefilling stage,a hot polymer melt rapidlyfills a cold mold reproducing a cavity of the desired product shape. During the packing/holding stage,the pressure is raised and extra material is forced into the mold to compensate for the effects that both temperature decrease and crystallinity development determine on density during solidification.The cooling stage starts at the solidification of a thin section at cavity entrance (gate),starting from that instant no more material can enter or exit from the mold impression and holding pressure can be released.When the solid layer on the mold surface reaches a thickness sufficient to assure required rigidity,the product is ejected from the mold.Due to the thermomechanical history experienced by the polymer during processing,macromolecules in injection-molded objects present a local order.This order is referred to as‘morphology’which literally means‘the study of the form’where form stands for the shape and arrangement of parts of the object.When referred to polymers,the word morphology is adopted to indicate:–crystallinity,which is the relative volume occupied by each of the crystalline phases,including mesophases;–dimensions,shape,distribution and orientation of the crystallites;–orientation of amorphous phase.R.Pantani et al./Prog.Polym.Sci.30(2005)1185–1222 1186R.Pantani et al./Prog.Polym.Sci.30(2005)1185–12221187Apart from the scientific interest in understandingthe mechanisms leading to different order levels inside a polymer,the great technological importance of morphology relies on the fact that polymer character-istics (above all mechanical,but also optical,electrical,transport and chemical)are to a great extent affected by morphology.For instance,crystallinity has a pro-nounced effect on the mechanical properties of the bulk material since crystals are generally stiffer than amorphous material,and also orientation induces anisotropy and other changes in mechanical properties.In this work,a thorough analysis of the effect of injection molding operative conditions on morphology distribution in moldings with particular reference to crystalline materials is performed.The aim of the paper is twofold:first,to outline the state of the art on the subject;second,to present an example of the characterization required for asatisfactorilyR.Pantani et al./Prog.Polym.Sci.30(2005)1185–12221188understanding and description of the phenomena, starting from material description,passing through the monitoring of the process cycle and arriving to a deep analysis of morphology distribution inside the mold-ings.To these purposes,fully characterized injection molding tests were performed using an isotactic polypropylene,previously carefully characterized as far as most of properties of interest,in particular quiescent nucleation density,spherulitic growth rate and rheological properties(viscosity and relaxation time)were determined.The resulting moldings mor-phology(in terms of distribution of crystallinity degree, molecular orientation and crystals structure and dimensions)was analyzed by adopting different experimental techniques(optical,electronic and atomic force microscopy,IR and WAXS analysis).Final morphological characteristics of the samples were compared with the predictions of a simulation code developed at University of Salerno for the simulation of the injection molding process.The effects of both injectionflow rate and mold temperature were analyzed.1.1.Morphology distribution in injection molded iPP parts:state of the artFrom many experimental observations,it is shown that a highly oriented lamellar crystallite microstructure, usually referred to as‘skin layer’forms close to the surface of injection molded articles of semi-crystalline polymers.Far from the wall,the melt is allowed to crystallize three dimensionally to form spherulitic structures.Relative dimensions and morphology of both skin and core layers are dependent on local thermo-mechanical history,which is characterized on the surface by high stress levels,decreasing to very small values toward the core region.As a result,the skin and the core reveal distinct characteristics across the thickness and also along theflow path[1].Structural and morphological characterization of the injection molded polypropylene has attracted the interest of researchers in the past three decades.In the early seventies,Kantz et al.[2]studied the morphology of injection molded iPP tensile bars by using optical microscopy and X-ray diffraction.The microscopic results revealed the presence of three distinct crystalline zones on the cross-section:a highly oriented non-spherulitic skin;a shear zone with molecular chains oriented essentially parallel to the injection direction;a spherulitic core with essentially no preferred orientation.The X-ray diffraction studies indicated that the skin layer contains biaxially oriented crystallites due to the biaxial extensionalflow at theflow front.A similar multilayered morphology was also reported by Menges et al.[3].Later on,Fujiyama et al.[4] investigated the skin–core morphology of injection molded iPP samples using X-ray Small and Wide Angle Scattering techniques,and suggested that the shear region contains shish–kebab structures.The same shish–kebab structure was observed by Wenig and Herzog in the shear region of their molded samples[5].A similar investigation was conducted by Titomanlio and co-workers[6],who analyzed the morphology distribution in injection moldings of iPP. They observed a skin–core morphology distribution with an isotropic spherulitic core,a skin layer characterized by afine crystalline structure and an intermediate layer appearing as a dark band in crossed polarized light,this layer being characterized by high crystallinity.Kalay and Bevis[7]pointed out that,although iPP crystallizes essentially in the a-form,a small amount of b-form can be found in the skin layer and in the shear region.The amount of b-form was found to increase by effect of high shear rates[8].A wide analysis on the effect of processing conditions on the morphology of injection molded iPP was conducted by Viana et al.[9]and,more recently, by Mendoza et al.[10].In particular,Mendoza et al. report that the highest level of crystallinity orientation is found inside the shear zone and that a high level of orientation was also found in the skin layer,with an orientation angle tilted toward the core.It is rather difficult to theoretically establish the relationship between the observed microstructure and processing conditions.Indeed,a model of the injection molding process able to predict morphology distribution in thefinal samples is not yet available,even if it would be of enormous strategic importance.This is mainly because a complete understanding of crystallization kinetics in processing conditions(high cooling rates and pressures,strong and complexflowfields)has not yet been reached.In this section,the most relevant aspects for process modeling and morphology development are identified. In particular,a successful path leading to a reliable description of morphology evolution during polymer processing should necessarily pass through:–a good description of morphology evolution under quiescent conditions(accounting all competing crystallization processes),including the range of cooling rates characteristic of processing operations (from1to10008C/s);R.Pantani et al./Prog.Polym.Sci.30(2005)1185–12221189–a description capturing the main features of melt morphology(orientation and stretch)evolution under processing conditions;–a good coupling of the two(quiescent crystallization and orientation)in order to capture the effect of crystallinity on viscosity and the effect offlow on crystallization kinetics.The points listed above outline the strategy to be followed in order to achieve the basic understanding for a satisfactory description of morphology evolution during all polymer processing operations.In the following,the state of art for each of those points will be analyzed in a dedicated section.1.1.1.Modeling of the injection molding processThefirst step in the prediction of the morphology distribution within injection moldings is obviously the thermo-mechanical simulation of the process.Much of the efforts in the past were focused on the prediction of pressure and temperature evolution during the process and on the prediction of the melt front advancement [11–15].The simulation of injection molding involves the simultaneous solution of the mass,energy and momentum balance equations.Thefluid is non-New-tonian(and viscoelastic)with all parameters dependent upon temperature,pressure,crystallinity,which are all function of pressibility cannot be neglected as theflow during the packing/holding step is determined by density changes due to temperature, pressure and crystallinity evolution.Indeed,apart from some attempts to introduce a full 3D approach[16–19],the analysis is currently still often restricted to the Hele–Shaw(or thinfilm) approximation,which is warranted by the fact that most injection molded parts have the characteristic of being thin.Furthermore,it is recognized that the viscoelastic behavior of the polymer only marginally influences theflow kinematics[20–22]thus the melt is normally considered as a non-Newtonian viscousfluid for the description of pressure and velocity gradients evolution.Some examples of adopting a viscoelastic constitutive equation in the momentum balance equations are found in the literature[23],but the improvements in accuracy do not justify a considerable extension of computational effort.It has to be mentioned that the analysis of some features of kinematics and temperature gradients affecting the description of morphology need a more accurate description with respect to the analysis of pressure distributions.Some aspects of the process which were often neglected and may have a critical importance are the description of the heat transfer at polymer–mold interface[24–26]and of the effect of mold deformation[24,27,28].Another aspect of particular interest to the develop-ment of morphology is the fountainflow[29–32], which is often neglected being restricted to a rather small region at theflow front and close to the mold walls.1.1.2.Modeling of the crystallization kineticsIt is obvious that the description of crystallization kinetics is necessary if thefinal morphology of the molded object wants to be described.Also,the development of a crystalline degree during the process influences the evolution of all material properties like density and,above all,viscosity(see below).Further-more,crystallization kinetics enters explicitly in the generation term of the energy balance,through the latent heat of crystallization[26,33].It is therefore clear that the crystallinity degree is not only a result of simulation but also(and above all)a phenomenon to be kept into account in each step of process modeling.In spite of its dramatic influence on the process,the efforts to simulate the injection molding of semi-crystalline polymers are crude in most of the commercial software for processing simulation and rather scarce in the fleur and Kamal[34],Papatanasiu[35], Titomanlio et al.[15],Han and Wang[36],Ito et al.[37],Manzione[38],Guo and Isayev[26],and Hieber [25]adopted the following equation(Kolmogoroff–Avrami–Evans,KAE)to predict the development of crystallinityd xd tZð1K xÞd d cd t(1)where x is the relative degree of crystallization;d c is the undisturbed volume fraction of the crystals(if no impingement would occur).A significant improvement in the prediction of crystallinity development was introduced by Titoman-lio and co-workers[39]who kept into account the possibility of the formation of different crystalline phases.This was done by assuming a parallel of several non-interacting kinetic processes competing for the available amorphous volume.The evolution of each phase can thus be described byd x id tZð1K xÞd d c id t(2)where the subscript i stands for a particular phase,x i is the relative degree of crystallization,x ZPix i and d c iR.Pantani et al./Prog.Polym.Sci.30(2005)1185–1222 1190is the expectancy of volume fraction of each phase if no impingement would occur.Eq.(2)assumes that,for each phase,the probability of the fraction increase of a single crystalline phase is simply the product of the rate of growth of the corresponding undisturbed volume fraction and of the amount of available amorphous fraction.By summing up the phase evolution equations of all phases(Eq.(2))over the index i,and solving the resulting differential equation,one simply obtainsxðtÞZ1K exp½K d cðtÞ (3)where d c Z Pid c i and Eq.(1)is recovered.It was shown by Coccorullo et al.[40]with reference to an iPP,that the description of the kinetic competition between phases is crucial to a reliable prediction of solidified structures:indeed,it is not possible to describe iPP crystallization kinetics in the range of cooling rates of interest for processing(i.e.up to several hundreds of8C/s)if the mesomorphic phase is neglected:in the cooling rate range10–1008C/s, spherulite crystals in the a-phase are overcome by the formation of the mesophase.Furthermore,it has been found that in some conditions(mainly at pressures higher than100MPa,and low cooling rates),the g-phase can also form[41].In spite of this,the presence of different crystalline phases is usually neglected in the literature,essentially because the range of cooling rates investigated for characterization falls in the DSC range (well lower than typical cooling rates of interest for the process)and only one crystalline phase is formed for iPP at low cooling rates.It has to be noticed that for iPP,which presents a T g well lower than ambient temperature,high values of crystallinity degree are always found in solids which passed through ambient temperature,and the cooling rate can only determine which crystalline phase forms, roughly a-phase at low cooling rates(below about 508C/s)and mesomorphic phase at higher cooling rates.The most widespread approach to the description of kinetic constant is the isokinetic approach introduced by Nakamura et al.According to this model,d c in Eq.(1)is calculated asd cðtÞZ ln2ðt0KðTðsÞÞd s2 435n(4)where K is the kinetic constant and n is the so-called Avrami index.When introduced as in Eq.(4),the reciprocal of the kinetic constant is a characteristic time for crystallization,namely the crystallization half-time, t05.If a polymer is cooled through the crystallization temperature,crystallization takes place at the tempera-ture at which crystallization half-time is of the order of characteristic cooling time t q defined ast q Z D T=q(5) where q is the cooling rate and D T is a temperature interval over which the crystallization kinetic constant changes of at least one order of magnitude.The temperature dependence of the kinetic constant is modeled using some analytical function which,in the simplest approach,is described by a Gaussian shaped curve:KðTÞZ K0exp K4ln2ðT K T maxÞ2D2(6)The following Hoffman–Lauritzen expression[42] is also commonly adopted:K½TðtÞ Z K0exp KUÃR$ðTðtÞK T NÞ!exp KKÃ$ðTðtÞC T mÞ2TðtÞ2$ðT m K TðtÞÞð7ÞBoth equations describe a bell shaped curve with a maximum which for Eq.(6)is located at T Z T max and for Eq.(7)lies at a temperature between T m(the melting temperature)and T N(which is classically assumed to be 308C below the glass transition temperature).Accord-ing to Eq.(7),the kinetic constant is exactly zero at T Z T m and at T Z T N,whereas Eq.(6)describes a reduction of several orders of magnitude when the temperature departs from T max of a value higher than2D.It is worth mentioning that only three parameters are needed for Eq.(6),whereas Eq.(7)needs the definition offive parameters.Some authors[43,44]couple the above equations with the so-called‘induction time’,which can be defined as the time the crystallization process starts, when the temperature is below the equilibrium melting temperature.It is normally described as[45]Dt indDtZðT0m K TÞat m(8)where t m,T0m and a are material constants.It should be mentioned that it has been found[46,47]that there is no need to explicitly incorporate an induction time when the modeling is based upon the KAE equation(Eq.(1)).1.1.3.Modeling of the morphology evolutionDespite of the fact that the approaches based on Eq.(4)do represent a significant step toward the descriptionR.Pantani et al./Prog.Polym.Sci.30(2005)1185–12221191of morphology,it has often been pointed out in the literature that the isokinetic approach on which Nakamura’s equation (Eq.(4))is based does not describe details of structure formation [48].For instance,the well-known experience that,with many polymers,the number of spherulites in the final solid sample increases strongly with increasing cooling rate,is indeed not taken into account by this approach.Furthermore,Eq.(4)describes an increase of crystal-linity (at constant temperature)depending only on the current value of crystallinity degree itself,whereas it is expected that the crystallization rate should depend also on the number of crystalline entities present in the material.These limits are overcome by considering the crystallization phenomenon as the consequence of nucleation and growth.Kolmogoroff’s model [49],which describes crystallinity evolution accounting of the number of nuclei per unit volume and spherulitic growth rate can then be applied.In this case,d c in Eq.(1)is described asd ðt ÞZ C m ðt 0d N ðs Þd s$ðt sG ðu Þd u 2435nd s (9)where C m is a shape factor (C 3Z 4/3p ,for spherical growth),G (T (t ))is the linear growth rate,and N (T (t ))is the nucleation density.The following Hoffman–Lauritzen expression is normally adopted for the growth rateG ½T ðt Þ Z G 0exp KUR $ðT ðt ÞK T N Þ!exp K K g $ðT ðt ÞC T m Þ2T ðt Þ2$ðT m K T ðt ÞÞð10ÞEqs.(7)and (10)have the same form,however the values of the constants are different.The nucleation mechanism can be either homo-geneous or heterogeneous.In the case of heterogeneous nucleation,two equations are reported in the literature,both describing the nucleation density as a function of temperature [37,50]:N ðT ðt ÞÞZ N 0exp ½j $ðT m K T ðt ÞÞ (11)N ðT ðt ÞÞZ N 0exp K 3$T mT ðt ÞðT m K T ðt ÞÞ(12)In the case of homogeneous nucleation,the nucleation rate rather than the nucleation density is function of temperature,and a Hoffman–Lauritzen expression isadoptedd N ðT ðt ÞÞd t Z N 0exp K C 1ðT ðt ÞK T N Þ!exp KC 2$ðT ðt ÞC T m ÞT ðt Þ$ðT m K T ðt ÞÞð13ÞConcentration of nucleating particles is usually quite significant in commercial polymers,and thus hetero-geneous nucleation becomes the dominant mechanism.When Kolmogoroff’s approach is followed,the number N a of active nuclei at the end of the crystal-lization process can be calculated as [48]N a ;final Zðt final 0d N ½T ðs Þd sð1K x ðs ÞÞd s (14)and the average dimension of crystalline structures can be attained by geometrical considerations.Pantani et al.[51]and Zuidema et al.[22]exploited this method to describe the distribution of crystallinity and the final average radius of the spherulites in injection moldings of polypropylene;in particular,they adopted the following equationR Z ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi3x a ;final 4p N a ;final 3s (15)A different approach is also present in the literature,somehow halfway between Nakamura’s and Kolmo-goroff’s models:the growth rate (G )and the kinetic constant (K )are described independently,and the number of active nuclei (and consequently the average dimensions of crystalline entities)can be obtained by coupling Eqs.(4)and (9)asN a ðT ÞZ 3ln 24p K ðT ÞG ðT Þ 3(16)where heterogeneous nucleation and spherical growth is assumed (Avrami’s index Z 3).Guo et al.[43]adopted this approach to describe the dimensions of spherulites in injection moldings of polypropylene.1.1.4.Modeling of the effect of crystallinity on rheology As mentioned above,crystallization has a dramatic influence on material viscosity.This phenomenon must obviously be taken into account and,indeed,the solidification of a semi-crystalline material is essen-tially caused by crystallization rather than by tempera-ture in normal processing conditions.Despite of the importance of the subject,the relevant literature on the effect of crystallinity on viscosity isR.Pantani et al./Prog.Polym.Sci.30(2005)1185–12221192rather scarce.This might be due to the difficulties in measuring simultaneously rheological properties and crystallinity evolution during the same tests.Apart from some attempts to obtain simultaneous measure-ments of crystallinity and viscosity by special setups [52,53],more often viscosity and crystallinity are measured during separate tests having the same thermal history,thus greatly simplifying the experimental approach.Nevertheless,very few works can be retrieved in the literature in which(shear or complex) viscosity can be somehow linked to a crystallinity development.This is the case of Winter and co-workers [54],Vleeshouwers and Meijer[55](crystallinity evolution can be drawn from Swartjes[56]),Boutahar et al.[57],Titomanlio et al.[15],Han and Wang[36], Floudas et al.[58],Wassner and Maier[59],Pantani et al.[60],Pogodina et al.[61],Acierno and Grizzuti[62].All the authors essentially agree that melt viscosity experiences an abrupt increase when crystallinity degree reaches a certain‘critical’value,x c[15]. However,little agreement is found in the literature on the value of this critical crystallinity degree:assuming that x c is reached when the viscosity increases of one order of magnitude with respect to the molten state,it is found in the literature that,for iPP,x c ranges from a value of a few percent[15,62,60,58]up to values of20–30%[58,61]or even higher than40%[59,54,57].Some studies are also reported on the secondary effects of relevant variables such as temperature or shear rate(or frequency)on the dependence of crystallinity on viscosity.As for the effect of temperature,Titomanlio[15]found for an iPP that the increase of viscosity for the same crystallinity degree was higher at lower temperatures,whereas Winter[63] reports the opposite trend for a thermoplastic elasto-meric polypropylene.As for the effect of shear rate,a general agreement is found in the literature that the increase of viscosity for the same crystallinity degree is lower at higher deformation rates[62,61,57].Essentially,the equations adopted to describe the effect of crystallinity on viscosity of polymers can be grouped into two main categories:–equations based on suspensions theories(for a review,see[64]or[65]);–empirical equations.Some of the equations adopted in the literature with regard to polymer processing are summarized in Table1.Apart from Eq.(17)adopted by Katayama and Yoon [66],all equations predict a sharp increase of viscosity on increasing crystallinity,sometimes reaching infinite (Eqs.(18)and(21)).All authors consider that the relevant variable is the volume occupied by crystalline entities(i.e.x),even if the dimensions of the crystals should reasonably have an effect.1.1.5.Modeling of the molecular orientationOne of the most challenging problems to present day polymer science regards the reliable prediction of molecular orientation during transformation processes. Indeed,although pressure and velocity distribution during injection molding can be satisfactorily described by viscous models,details of the viscoelastic nature of the polymer need to be accounted for in the descriptionTable1List of the most used equations to describe the effect of crystallinity on viscosityEquation Author Derivation Parameters h=h0Z1C a0x(17)Katayama[66]Suspensions a Z99h=h0Z1=ðx K x cÞa0(18)Ziabicki[67]Empirical x c Z0.1h=h0Z1C a1expðK a2=x a3Þ(19)Titomanlio[15],also adopted byGuo[68]and Hieber[25]Empiricalh=h0Z expða1x a2Þ(20)Shimizu[69],also adopted byZuidema[22]and Hieber[25]Empiricalh=h0Z1Cðx=a1Þa2=ð1Kðx=a1Þa2Þ(21)Tanner[70]Empirical,basedon suspensionsa1Z0.44for compact crystallitesa1Z0.68for spherical crystallitesh=h0Z expða1x C a2x2Þ(22)Han[36]Empiricalh=h0Z1C a1x C a2x2(23)Tanner[71]Empirical a1Z0.54,a2Z4,x!0.4h=h0Zð1K x=a0ÞK2(24)Metzner[65],also adopted byTanner[70]Suspensions a Z0.68for smooth spheresR.Pantani et al./Prog.Polym.Sci.30(2005)1185–12221193。
聚丙烯挤出成型实验报告(3篇)
第1篇一、实验目的本次实验旨在了解聚丙烯(PP)材料的挤出成型工艺,掌握挤出成型的基本原理和操作方法,并通过对实验结果的分析,探讨影响挤出成型质量的因素。
二、实验原理聚丙烯是一种热塑性树脂,具有良好的力学性能、耐化学性和耐热性。
挤出成型是聚丙烯材料常用的成型方法之一,通过挤出机将熔融的聚丙烯树脂经过模具成型,得到所需的塑料制品。
三、实验材料与设备1. 实验材料:聚丙烯(PP)颗粒2. 实验设备:- 聚丙烯挤出机- 温控装置- 模具- 冷却水循环系统- 切割机- 电子天平- 光学显微镜四、实验步骤1. 准备工作- 将聚丙烯颗粒过筛,去除杂质。
- 将挤出机预热至设定温度。
2. 原料塑化- 将过筛的聚丙烯颗粒加入挤出机料斗。
- 启动挤出机,使聚丙烯颗粒在挤出机内塑化熔融。
3. 挤出成型- 调整模具,使其符合所需产品的形状和尺寸。
- 控制挤出机的转速和温度,使熔融的聚丙烯树脂通过模具成型。
4. 冷却和切割- 将成型后的产品通过冷却水循环系统冷却至室温。
- 使用切割机将冷却后的产品切割成所需长度。
5. 检验- 使用电子天平称量产品的重量,检查其尺寸精度。
- 使用光学显微镜观察产品的表面和断面,检查其外观和内部结构。
五、实验结果与分析1. 产品外观- 产品表面光滑,无气泡、裂纹等缺陷。
2. 产品尺寸- 产品尺寸符合设计要求,尺寸精度较高。
3. 产品内部结构- 产品内部结构均匀,无分层、杂质等缺陷。
4. 影响因素分析- 温度:温度对挤出成型质量有较大影响。
过高或过低的温度都会导致产品出现缺陷。
实验中发现,当温度过高时,产品易出现熔融流淌;温度过低时,产品易出现结晶不良。
- 转速:转速对产品的尺寸和外观有较大影响。
转速过高或过低都会导致产品出现尺寸偏差和表面缺陷。
- 模具:模具的形状和尺寸对产品的形状和尺寸有直接影响。
模具设计不合理会导致产品出现尺寸偏差和表面缺陷。
六、实验结论本次实验成功地进行了聚丙烯挤出成型,得到了符合设计要求的产品。
注塑模具毕业设计论文
前言塑料模具技术的发展日新月异,在现代工业、餐具、玩具等行业中的应用很广泛,模具是生产各种产品的重要工艺装备。
此次毕业设计的题目是塑料成型模具的设计。
塑料模具的分类很多,按照塑料制件的不同可分为:注射模、压缩模、压注模、挤出模、气动成型模等。
注塑模具又称注塑成型,是热塑性塑料制品生产的一种重要的方法。
除少数塑料制品外,几乎所有的热塑性塑料都可以用注射成型方法生产塑料制品。
注塑模具不仅用于热塑性塑料的成型,而且成功用于热固性塑料的成型。
模具以其特定的形状通过一定的方式使原料成型。
模具的制造精度越高,制造成本越高,因此应延长模具的使用寿命,尽量缩短模具的制造周期,来降低生产成本。
塑料制品以其密度小、质量轻的优点在工业中的应用日益普遍,大有“以塑代钢”的趋势。
塑料模具可以满足塑料的加工工艺要求和使用要求,可以很好的降低塑料制品的生产成本。
塑料的质量要靠模具的正确结构和模具成型零件的正确形状,精确尺寸几较低的表面粗糙度来保证。
本次设计的模具用于有机玻璃制品的生产制造。
聚甲基丙烯酸甲酯(PMMA),俗称有机玻璃,属于热塑性刚性硬质无色的透明材料,具有良好的综合力学性能及电绝缘性,制品尺寸稳定,容易成型,有一定的耐热性、耐寒性和耐气候性,表面硬度不够,容易擦伤,易溶于有机溶剂,又可以软化熔融,可再次成型为一定形状的制品,如此可反复多次。
因此选用该塑料有助于废料和旧弃塑件的二次回收,循环利用。
有一定的环保效应,减少了现实中的“白色污染”。
第一章塑件成型工艺分析第1.1节塑件分析1.1.1 塑件二维工作图如图1-1所示图1-11.1.2 塑件1.塑件材料名称有机玻璃(PMMA);2.色调无色透明;3.生产纲领大批量;4.塑件结构该塑件外形为长方体类零件,但内有凹腔和凸台,塑件壁厚均约为2mm,其脱模斜度为30/~1°30/(取1°),采用一般精度等级MT5级。
第1.2节塑件原料(PPMA)的工艺性能1.2.1 支架底托的原料聚甲基丙烯酸甲酯(PMMA)1.物料性能聚甲基丙烯酸甲酯是刚性硬质无色的透明材料,具有良好的综合力学性能及电绝缘性,制品尺寸稳定,容易成型,有一定的耐热性、耐寒性和耐气候性,易溶于有机溶剂,表面硬度不够,容易擦伤。
注塑模毕业设计【范本模板】
CHANGZHOU INSTITUTE OF TECHNOLOGY毕业设计说明书题目:U型座3D造型及注塑模设计二级学院:机械与车辆工程学院专业: 材料成型班级:12成型2 学生姓名:徐晨阳学号:12011027 指导教师:伊启平职称: 高级讲师评阅教师: 田文彤职称:副教授2016年06 月摘要根据所学的知识,本次设计,我选的是U型座的注塑模设计。
这次毕业设计是利用计算辅助而展开的,分为两个阶段完成(机械部分和计算机部分)。
先利用PROE制作零件三维图,分析制件基本属性。
然后选择注射机(海天SA1200/410U),并设计其组成机构内容。
最后完成零件的装配图和零件图.关键词:侧抽芯斜导柱 PROE Moldflow 计算校核Abs tractAccording to the knowledge,the design,I choose is U type of injection mold design.This graduation design is to use, calculation of the auxiliary which is divided into two stages (mechanical parts, and computer).Parts are manufactured using PROE 3D figure,occurring basic attribute。
Then select the injection machine (HaitianSA1200/410U).And And design the content of institutions.The finished parts assembly drawing and part drawingKeywords:Mobile phone battery cover slider angle pin PROE MOLDFLOW Calculating Proofread目录摘要 (1)Abstract (2)第1章前言 (9)1.1 塑料成型模具的分类及注塑模 (9)1.2 选题的意义和依据 (9)1。
电缆毕业设计-挤塑
目录摘要 (2)绪论3第一章设备41.1 塑料挤出生产线41.2 料挤出机螺杆51.3 温度系统9第二章制造工艺112.1 塑料的挤制112.2 塑料挤出工艺132.3 模具14第三章废品的种类及排除方法203.1 焦烧203.2 塑化不良213.3 疙瘩213.4 塑料层正负超差223.5 电缆外径粗细不均和竹节形233.6 合胶缝不好243.7 其它缺陷 (24)3.8 不良的修复方法26总结29致谢错误!未定义书签。
参考文献30摘要在电线电缆行业中,挤塑工艺的应用越来越普及,引起了生产方和使用用户的热切关注。
本篇论文共分以下几个部分,对挤塑工艺进行了详尽的描述。
第一部分介绍挤塑生产设备及其工作原理;第二部分分析了塑料挤出的原则与工艺要求并对模具进行了详细介绍以及对塑料的注塑工艺参数的分析;第三部分归纳了挤塑不良品产生的原因及解决的办法。
关键词:挤塑,模具,工艺,焦烧ABSTRACTWire and cable industry, Applied Extrusion Process growing popularity caused the production and use of great concern to users.This paper is divided intoseveral parts,theextrusion processis described in detail.The first part introduces theextrusion productionequipment and its workingprinciple;the second partanalyzestheprinciple andtechnical requirements ofplastic extrusionand dieare introduced in detailas well as onplasticinjection molding process parametersanalysis;the third part summarizesextrusiondefect causeand solution.Key words: Extrusion ,Mold,Technology,Burning绪论塑料电线电缆在国民经济各个部门使用很广泛,原因是它本身具有电气性能好、力学性能优越、耐化学腐蚀、容易加工、工艺流程较短、技术操作简便、材料来源丰富、成本较低等优点。
管材挤出成型实验报告(3篇)
第1篇一、实验目的1. 理解管材挤出成型工艺的基本原理和流程。
2. 掌握挤出机、模具、冷却装置等主要设备的使用方法。
3. 通过实验,观察和掌握管材挤出成型过程中温度、压力、牵引速度等参数对管材质量的影响。
4. 分析实验数据,探讨提高管材成型质量的方法。
二、实验原理管材挤出成型是利用挤出机将熔融塑料通过模具挤出成管状制品的过程。
该过程主要包括以下几个步骤:1. 塑料粒料通过料斗进入挤出机,在螺杆的旋转和加热作用下,熔融并塑化。
2. 熔融塑料通过模具挤出,形成管坯。
3. 管坯经过冷却装置冷却定型,成为具有一定壁厚的管材。
4. 管材通过牵引设备匀速拉出,并按规定长度切断。
三、实验设备与材料1. 实验设备:挤出机、模具、冷却装置、牵引设备、切割设备、温度控制器、压力表等。
2. 实验材料:聚氯乙烯(PVC)粒料。
四、实验步骤1. 准备实验设备,检查各部分工作状态。
2. 根据实验要求,调整挤出机的温度、压力、转速等参数。
3. 将PVC粒料加入料斗,启动挤出机进行加热和塑化。
4. 当挤出机出口处有稳定的熔融塑料流出时,关闭料斗,开始挤出实验。
5. 调整牵引设备的速度,使管材匀速拉出。
6. 观察并记录管材的挤出过程,包括温度、压力、牵引速度等参数。
7. 当管材达到预定长度后,停止牵引设备,切断管材。
8. 收集实验数据,进行分析和总结。
五、实验结果与分析1. 温度对管材质量的影响:温度过高,会导致管材壁厚不均匀、表面出现气泡;温度过低,则会使管材硬度过高、表面出现裂纹。
因此,应控制合适的温度,以保证管材质量。
2. 压力对管材质量的影响:压力过高,会使管材壁厚不均匀、表面出现凹陷;压力过低,则会使管材壁厚过薄、表面出现皱纹。
因此,应控制合适的压力,以保证管材质量。
3. 牵引速度对管材质量的影响:牵引速度过高,会使管材壁厚不均匀、表面出现裂纹;牵引速度过低,则会使管材出现松弛、变形。
因此,应控制合适的牵引速度,以保证管材质量。
塑料模塑成型毕业设计说明书 精品
目录1 绪论 (1)2 塑件分析 (3)2.1 塑件的使用要求 (3)2.2 塑件的原料 (3)2.3 塑件的整体分析 (3)2.3.1 塑件的形状 (3)2.3.2 塑件的壁厚 (3)3 注射机的选用 (5)3.1 浇注体积的确定 (5)3.1.1 零件体积的计算 (5)3.1.2 型腔数目的确定 (5)3.1.3 浇注系统的体积 (5)3.2 根据浇注体积选取注射机 (5)4 浇注系统的设计 (7)4.1 主流道和冷料穴的设计 (7)4.2 定位圈的设计 (8)4.3 分流道的设计 (9)4.4 侧浇口的设计 (10)5 成型零件结构设计与计算 (11)5.1 成型零件结构的设计 (11)5.1.1 凹模结构 (11)5.1.2 分型面 (11)5.2 成型零件的工作尺寸计算 (12)5.2.1 型腔直径计算 (12)5.2.2 型芯直径的计算 (15)5.2.3 型腔深度的计算 (17)5.2.4 型芯高度的计算 (18)5.2.5 圆心距的计算 (19)5.3 模具型腔侧壁和底板厚度的计算 (19)5.3.1 凹模壁厚的计算 (19)6 温度调节系统的设计 (21)6.1 冷却系统的分析计算 (21)7 脱模机构的设计 (23)7.1 脱模方式的总述 (23)7.2 推出机构的设计 (23)8 排气系统的设计 (24)9 标准件的选用 (25)9.1 标准模架的选择 (25)9.2 导向机构的选用 (26)9.2.1 导柱的计算 (26)9.2.2 导套的设计 (27)9.3 拉料杆和推杆的计算 (28)9.3.1 小端拉料杆的计算 (28)9.3.2 大端推杆的计算 (28)9.4 弹簧的选择 (28)9.5 销钉的选择 (28)9.6 镶件的确定 (29)9.7 模具材料 (29)10 注射机的校核 (30)10.1 注射机的校核 (30)10.1.1 最大注塑量的校核 (30)10.1.2 注射压力校核 (30)10.2 锁模力的校核 (30)10.3 模具与注塑机合模部分相关尺寸的校核 (31)10.4 开模行程的校核 (31)11 总结 (33)参考文献 (35)致谢 (37)附录 (39)1 绪论1 绪论塑料工业由塑料原料生产和塑料制品生产两大系统组成,二者相辅相成,缺一不可,而塑料制品生产是实现塑料原料自身价值的唯一手段。
PVC管材挤出课程设计
湖南科技大学题目PVC管材挤出课程设计指导老师学院专业学号作者彭耀威二〇一一年六月二十八日目录1 概述 (2)PVC管材的特点 (2)PVC的污染 (2)PVC管材行业的现状和应用前景 (3)国内外要紧工艺线路的比较和选择 (4)原料的选择和生产配方 (5)产品的质量指标 (7) (8)挤出成型工艺 (8)定型工艺 (8)牵引工艺 (9)生产流程 (9) (10)生产能力计算 (10)物料衡算 (10) (11)螺杆挤出机计算 (11)挤出管辅机计算 (11)其他设备 (11)原料消耗计算 (11)能量衡算 (12) (13)设备一览表 (14)第一章概述聚氯乙烯(PVC)是世界第二大通用树脂,是由氯乙烯单体(VCM)聚合而成的一种热塑性高分子化合物。
聚氯乙烯管主若是指硬质聚氯乙烯管,在ISO标准中概念为Unplasticized Polyvinyl Chloride,简称为PVC-U。
聚氯乙烯管材的特点与钢、铁、混凝土、陶瓷管相较,聚氯乙烯管材具有如下优势:①重量轻,硬质聚氯乙烯管的相对密度为,仅为同尺寸钢重量的1/6,1 t塑料管可代替10~13 t铸铁管,运输安装容易。
②耐侵蚀性能好。
③电绝缘性能好,其体积电阻约为1×10 ~3×10 n•cm,击穿电压达23~28 Kv/mm。
④摩擦阻力小。
管内流体速度比钢管高30%左右,且结垢少,不生锈,长期运输水和其他流体,流率和流量均能维持不变;而铁管会生锈、结垢,利用数年后管内流率和流量均要减少。
⑤导热系数小,耐候性较好,隔热性能好。
⑥着色方便,不需油漆,且容易制成各类标识颜色的管材,生产中能耗低,仅为铸铁管的%。
1.2PVC的污染PVC内一些有毒和增塑剂,可能渗出或气化;部份添加剂会干扰生物内分泌(阻碍生殖性能),部份可增加致癌风险;焚化PVC垃圾会产生致癌的二恶英而污染大气。
常规的PVC材料,如电线、电缆等是相当严峻的污染源。
透明PC板材挤出成型工艺设计_毕业设计论文
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挤出成型实验报告
竭诚为您提供优质文档/双击可除挤出成型实验报告篇一:cmt挤出实验报告实验二pp/pe双螺杆挤出实验目的1.理解双螺杆挤出机的基本工作原理,学习挤出机的操作方法。
2.了解聚烯烃挤出的基本程序和参数设置原理。
实验原理在塑料制品的生产过程中,自聚合反应至成行加工前,一般都要经过一个配料混炼环节,以达到改善其使用性能或降低成本等目的。
传统方法是用开炼机和密炼机,但是效率低下,不能满足生产提高的需要,随后便产生了单螺杆挤出机,继而发展了双螺杆挤出机。
双螺杆挤出机具有塑化能力强,挤出效率高,耗能低,混炼效果好,自清洁能力等吸引了塑料行业的注意并取得了迅速发展。
另外挤出机也是塑料生产应用最广泛的机器,使用不同的机头可以挤出不同的产品,如型材、片材、管材和挤出吹膜等。
因而挤出机在塑料加工行业有其它机器无法替代的重要性。
本实验使用双螺杆挤出机挤出物料切粒,是生产色母料的工艺过程,如果在侧喂料口或者将物料与颜料在捏合机中混合加料,挤出的产品则为色母料,另外如果换为其它机头即可用于生产各种相应产品。
同向旋转双螺杆挤出机组的结构与其它挤出设备一样,包括传动部分、挤压部分、加热冷却系统、电气与控制系统及机架等。
由于双螺杆挤出机物料输送原理和单螺杆挤出机不同,通常还有定量加料装置。
鉴于同向双螺杆挤出机在塑料的填充、增强和共混改性方面的应用,为适应所加物料的特点及操作的需要,通常在料筒上都设有排气口及一个以上的侧加料口,同时把螺杆上承担输送、塑化、混合和混炼功能的螺纹制成可根据需要任意组合的块状元件,像糖葫芦一样套装在芯轴上,称为积木组合式螺杆,其整机也称为同向旋转积木组合式双螺杆挤出机。
挤出机的结构包括以下几个部分:(1)传动部分传动部分就是带动螺杆转动的部分,它通常由电动机、减速箱和轴承等组成,在挤出过程中,要求螺杆在一定的转速范围内运转,转速稳定,不随螺秆负荷的变化而变化,以保证制品的质量均匀一致。
为此。
传动部分一般采用交流整流电动机、直流电动机等装置。
矿泉水瓶挤出吹塑成型工艺及模具设计(本科毕业论文)
1.3
众所周知,塑料是当今世界各国国民经济各个部门及人们生活领域中广泛使用的一种新型结构材料。据调查,近几年来,塑料制品在我国的应用情况大致如下所示:在建筑材料工业的应用占10%;包装工业占的比例为25%;电器、电子信息工业占的比例高达10%;汽车及其他交通工业的应用占2%;农业中的应用占15%;轻工业(含日用品、服装、鞋、玩具、游戏机、体育用品等)所占的比重高达27%;机械工业(含医疗器械)占2%,其它的占9%的比重。估计在今后几年,塑料制品在建筑材料工业、包装工业、特别是汽车工业、电器、电子、通信工业、农业中的农膜节能、节水、排灌、滴灌、微灌设备中使用的比重将会有很大的提高。[2]
塑料板、管、型材总产值2143.00亿元,同比增长32.29%;塑料丝绳及编制品总产值1030.63亿元,同比增长29.33%;塑料零件总产值932.92亿元,同比增长11.91%;塑料包装箱及容器总产值895.69亿元,同比增长20.34%;日用塑料杂品总产值787.16亿元,同比增长14.02%;泡沫塑料总产值501.14亿元,同比增长13.60%;塑料鞋总产值243.67亿元,同比增长23.33%;其他塑料制品总产值1201.64亿元,同比增长23.60%。在国家推动节能减排和循环经济发展政策、经济和技术创新、社会主义新农村建设速度发展加快、城市化进程不断推进、人们生活水平大幅提高、促使国内消费上升等积极因素都进一步推动了塑料行业的大发展,产业规模在不断扩大,产品产量逐年增加,主要经济技术指标大幅度递增,全行业不断发展壮大,正沿着为实现塑料工业由大国到强国的可持续发展之路迈进。
塑料挤出机毕业设计范文
塑料挤出机毕业设计范文摘要:本文介绍了一种基于塑料挤出机的设计方案。
该方案主要包括了机器的结构设计、传动系统的选择和控制系统的设计。
该挤出机具有高效、独立调节和自动化控制的特点,可以满足不同类型塑料产品的生产需求。
1.引言塑料挤出机是一种常用的塑料加工设备,广泛应用于塑料制品生产。
随着科技的发展,各种新型塑料材料出现不断涌现,对塑料挤出机的设计和改进提出了更高的要求。
本文将基于已有挤出机的设计基础,改进其结构、传动系统和控制系统,以实现更高效、更准确的塑料挤出过程。
2.结构设计挤出机主要由料斗、加料口和螺杆组成。
在结构设计上,我们将考虑以下几个因素:(1)螺杆结构:螺杆的直径和纵向螺距应根据塑料材料的特性和需求来确定。
同时,螺杆的材料应选择优质的合金钢,以确保其耐磨性和耐腐蚀性。
(2)加热系统:挤出机需要加热来提高塑料的流动性,以便顺利挤出。
因此,在结构设计上,需要加入适当的加热系统,例如电加热管或热风机,以确保材料能够在所需温度下顺利挤出。
(3)冷却系统:挤出机的冷却系统非常重要,可以通过冷却风扇或水冷却系统来实现。
冷却系统的设计应考虑到塑料挤出过程中的热量产生,以确保挤出物在冷却过程中能够保持理想的形状。
(4)机架:挤出机的机架应选用坚固的材料,以确保机器的稳定性和安全性。
3.传动系统的选择传动系统是塑料挤出机的核心组成部分之一,其选择直接影响到挤出机的性能和效率。
目前,常见的传动系统有液压传动和电动传动。
在本设计中,我们将选择电动传动系统,具体原因如下:(1)电动传动系统具有更高的效率和更快的反应速度,可以在短时间内实现快速运动和停止。
(2)电动传动系统更加安全可靠,不易泄漏和故障。
(3)电动传动系统的维护成本较低,寿命较长。
4.控制系统的设计为了实现塑料挤出机的独立调节和自动化控制,我们将设计一个基于PLC的控制系统。
该控制系统可以实时监控挤出机的温度、压力和速度等参数,并通过传感器和执行器对其进行调节。
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毕业设计(论文)任务书
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摘要
本文是关于工业用塑料聚合物双螺杆挤出机的设计。
在工业上和实验室中,螺杆挤出机都应用及其普遍,是塑料加工设备的重要元部件之一。
作为工业中使用的双螺杆挤出机,在设计过程中,除了要求能够完成固体输送、增压、熔融、熔体输送和泵压等一系列通用过程以外,还要求涉及到复合塑料与聚合物颗粒之间的混合,以及物料喂料量的操纵。
物料喂料量的操纵则是通过操纵主螺杆及其辅助喂料螺杆的转速来完成的。
同时,双螺杆挤出机具有分布混合和分散混合效果良好、自洁作用较强、可实现高速运转、产量高等特点,特不适合聚合物的改性,如共混、填料、增强及反应挤出。
有利于增加挤出机的挤出产量,提高塑化质量。
关键词:双螺杆挤出机;辅助喂料螺杆;工业;同向啮合
目录
1、绪论 (1)
1.1 塑料挤出成型概述 (1)
1.2塑料挤出成型的差不多特点 (1)
1.3塑料挤出成型设备的组成 (2)
1.4 挤出机的分类 (3)
1.5 挤出机的选择原则和方法 (3)
1.6 挤出螺杆的选择 (3)
2、同向啮合双螺杆挤出机 (4)
2.1 挤出机型号讲明 (4)
2.2 挤出成型差不多原理 (5)
2.3 同向啮合双螺杆挤出机工作原理及其特性 (7)
2.4本次所设计挤出机类型的确定 (7)
2.5 同向啮合双螺杆挤出机的要紧技术参数和规格.. 7
3、同向啮合双螺杆挤出机性能参数的选择 (8)
3.1螺杆直径的选择 (8)
3.2螺杆中心距公称尺寸的选择 (8)
3.3螺杆长径比的选择 (8)
3.4螺杆转速要求及范围的选择 (9)
3.5 挤出机功率的确定 (9)
3.6挤出机加热功率的确定 (9)
4、同向啮合双螺杆挤出机要紧零部件的设计 (9)
4.1 主螺杆的设计 (10)
4.2机筒的设计 (11)
4.3 螺杆与机筒的配合要求 (12)
4.4分流板及过滤网 (12)
4.5料斗的设计 (12)
5 挤出机电机的选择 (13)
6 减速器的设计 (13)
6.1 传动方案的总体设计 (13)
6.2齿轮设计 (13)
6.3 齿轮轴的设计 (24)
6.6 箱体的设计 (38)
结束语 (40)
参考文献 (41)
致谢 (42)。