液晶聚合物成型技术探讨

介绍液晶聚合物(LCP)的工艺特性，指出注射模设计的要点和注塑机选用的要求，阐述成型中料筒温度、模具温度、注塑压力、注射速率和时间等工艺参数确定的原则。并详细介绍几种典型LCP材料注射成型工艺、成型加工要点和注意事项。     

聚碳酸酯的注射成型工艺

分析了聚碳酸酯的注射成型工艺特性，讨论了影响聚碳酸酯制品质量的工艺因素，包括模具与设备、制品与嵌件结构、原材料干燥、注射温度、注射速率、注塑压力、成型周期、模具温度、制品后处理等。总结了聚碳酸酯注射成型制品常见的缺陷及解决措施。     

模具对振动注射成型制件作用效应的初步研究

采用自制的振动试验台，分别安装两个不同的试样模具，使用了不同的聚合物材料，在不同的温度，压力下变化不同的振动频率和振幅进行实验，研究了聚合物熔体在振动场中注射成型时，成型模具对聚合物振动成型效应的作用。结果表明，模具浇口及型腔尺寸不同。振动注射制件的强度不同；模具型腔尺寸大振动产生的效应弱。型腔小振动产生的效应强。     

微孔塑料注射成型制品体积收缩与翘曲变形数值分析

采用Moldflow软件，通过微孔注射成型过程的数值模拟，系统研究了熔体注射温度、模具温度对其体积收缩、翘曲变形和残余应力的影响规律，并基于流变学理论，揭示了其影响机理。研究结果表明，随着熔体注射温度和模具温度增加，微孔注射制品翘曲变形和残余应力均增加，成型制品的体积收缩随着熔体注射温度升高而增加，而随着模具温度升高而减小。本研究为微孔注射成型工艺和模具的设计提供理论指导。     

玻璃纤维增强聚丙烯制品翘曲变形的研究

针对玻璃纤维增强聚丙烯(PP/GF)注射成型制品存在的翘曲变形缺陷,研究了注射工艺参数如模具温度、喷嘴温度、注射速率、保压压力和保压时间对制品成型收缩率及翘曲的影响。结果表明,随着模具温度、喷嘴温度和保压压力的降低,制品的翘曲减小;适当提高注射速率和减少保压时间也可减小制品翘曲。     

塑料成型加工实用技术讲座(第三讲) 注射成型工艺对制品质量的影响

介绍注射成型工艺对制品质量的影响。指出注塑工艺参数主要有温度、压力、时间三类。对不同的塑料原料、模具结构、工艺参数的选择各不相同，且各工艺参数对制品质量的影响也有较大区别。在塑料原材料、模具结构一定的情况下，注射成型工艺参数的选取、设定对制品质量的作用显著。并指出了注射成型工艺参数的合理选用原则以及如何用PVT关系曲线对工艺参数进行优化。     

影响注射制品重量重复精度诸因素的分析研究

提高注射制品重量重复精度是注射成型科技进步的努力重要目标，注射制品重量重复精度是设备、模具、成型工艺等综合技术水平的标志。本文对影响注射制品重量重复精度的加热温度、塑化转速、注射压力、注射速度、螺杆特性、模具温控性能等主要因素，从理论和实践上作了比较具体的分析研究，提出了提高注射制品重复精度的具体措施，可供有关人士参考。     

壳体制品注塑工艺参数CAE优化分析

应用Moldflow软件对壳体制品注射成型工艺参数进行了优化分析,模拟出制品成型过程中的最佳注塑压力、锁模力、模具温度、熔体温度、注射时间、保压压力和保压时间、冷却时间。采用该成型工艺参数结合合理的注塑模具能注塑出最佳的塑料制品,为成型过程的顺利进行提供指导依据,模拟结果具有一定的理论意义及实际指导价值。     

塑料成型工艺和设计的若干改进

本文简述了成型工艺和设计的若干改进。在成型工艺的改进方面述及将聚甲醛作为胶结料的粉末注射成型系统；注射成型的机械技术，模具技术、制品取出系统，共注射成型，注射成型机的工序控制。在设计方面，简述了关于加强和防止成型品早期破损的设计。     

注塑成型中制品的缺陷原因及其对策

注塑成型是塑料成型中最重要的一种工艺,注塑制品应用于国民经济的各个领域。所谓热塑性树脂的注塑成型工艺,是指将树脂加热熔融,熔体借助压力注入模腔,经冷却固化而得到一定形状制品的成型方法。注塑过程中树脂需经过受热软化、熔融、注塑、保压、冷却定型等五个阶段的物理变化过程。树脂内部将会产生大分子定向、结晶以及残余应力等。由于注射成型过程中的成型条件（如注射压力、螺杆背压、注射速度、注射量、锁模力、料筒温度、模具温度）的选择不当或模具本身存在的问题,会使注塑制品出现许多不良现象和缺陷。归纳起来可分为五大类…     

聚苯硫醚的成型加工技术

叙述聚苯硫醚（PPS）作为一种性能优异的特种工程塑料，同时又是一种结晶性能热塑性树脂的性能特点及应用；论述了PPS的工艺特性，模具温度与结晶度的关系；介绍了PPS制品和模具的设计中应考虑 ;乡下离PPS制品的注塑工艺，后处理工艺以及超声波焊接工艺。     

Structure and properties of polyblends of a thermotropic liquid crystalline polymer with an alloy of polyamide-6 and ABS

The relationship between the microstructure and corresponding mechanical properties developed during injection molding of blends containing a liquid crystalline polymer (LCP) as the minor component and an engineering polymer system has been studied. A wholly aromatic copolyester LCP (Vectra A950) was melt blended at different compositions with a thermoplastic matrix consisting of a commercial compatibilized blend of polyamide-6 and ABS (Triax 1180). These blends were prepared under two different sets of injection molding conditions. In the first case, a higher melt temperature, higher barrel temperature, lower injection pressure, lower mold temperature, and shorter residence time in the mold were used during injection molding, as compared with the second case. The mechanical properties of the blends were superior to those of the base polymer. In the second case, the resulting injection-molded specimens had a distinct skin–core morphology where elongated fibrils of LCP constituted the skin layer. The mechanical properties of the blends processed under the second set of processing conditions were superior to those of the first, though the trends in both cases were the same. To study the effects of process variables the 15% LCP blend and the second set of processing conditions were taken as the base. Samples were injection-molded by varying one parameter at a time. It was seen that the properties of the blend were increased by maintaining a lower barrel temperature, greater injection pressure, lower injection speed, higher mold temperature, and a greater residence time in the heated mold. Thus it was found that the processing conditions played a vital role in determining the mechanical properties and morphology of the polyblends. © 1996 John Wiley & Sons, Inc.     

Advanced injection molding mold and molding process for improvement of weld line strengths and isotropy of glass fiber filled aromatic polyester LCP

An advanced injection molding tool for measurement of mechanical strength and anisotropy of liquid crystal polymers (LCP)/mineral filler composites was developed. The mold produces thin‐walled LCP specimens that can be used by water cutting technique for production of an injection molded flow direction test bar, a transverse‐to‐injection molded flow direction test bar, a test bar for knit line strength measurement, and a test bar for butt weld line strength measurement. This tool and its use for molding experiments were optimized by experimental research and by computational calculations based on experimental parameters obtained by molding of several LCP test materials. Different pressure profiles and different injection speeds were tested as well as application of mold overflow phenomenon in production of test specimens. It was observed that a pressure controlled X‐melt technique and on the other hand fast injection speeds with overflow in conventional molding methods gave the best strength and isotropy properties for the test specimens. Results indicate that the mold developed is useful for determination of anisotropic and weld line strength properties of LCP composites. When developing “isotropic LCP” by different possibilities of nanotechnology this tool significantly reduces time of LCP material and process development. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers     

Effects of processing conditions on birefringence development in injection molded parts. II. Experimental measurement

The birefringence of injection molded parts was measured using a digital photoelasticity system, which combines a digital image analysis technique and the half-fringe photoelasticity (HFP) method The effects of processing conditions, including melt temperature, mold temperature, filling time and packing pressure, on the birefringence development in the molded parts were investigated. It was found that temperature and pressure are the two dominant factors that determine the birefringence development in the parts during the molding process. Frozen-in birefringence of the molded parts decreases with increasing melt temperature, mold temperature and injection speed. Birefringence of the parts also increases with increased packing pressure, especially around the gate area. Numerical simulations using the Leonov viscoelastic fluid model predict similar dependence of birefringence of parts on processing conditions. Simulated results are also consistent with measured values.     

Hierarchy structure in injection molded polypropylene/ethylene–octane copolymer blends

In this article, the phase morphology and mechanical properties of polypropylene (PP)/ethylene–octane copolymer (POE) blends with fixed ratio (60/40) obtained via different processing conditions, including barrel temperature, injection speed, and mold temperature, have been investigated. SEM was carried out for detailed characterization of phase morphology from the skin to the core, layer by layer. It was interesting that for all the processing conditions no dispersed POE elastomer was observed in the skin layer but elongated POE particles with large size were observed in the subskin layer. From the transition zone to the core layer, an increased phase separation was observed, which could lead to a formation of cocontinuous morphology, depending on the processing condition used. Higher barrel temperature, lower mold temperature, and higher injection speed could result in a smaller size of POE phase. The tensile strength and impact strength were found not sensitive to barrel temperature and mold temperature but to the low injection speed, both tensile strength and impact strength had a higher value for specimen obtained via low injection speed. The formation of the skin‐core morphology and the effect of processing conditions on the phase morphology were discussed based on crystallization kinetics of PP matrix, rheology, and shear induced phase mixing. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

长玻纤增强聚甲醛注塑成型工艺的研究

制备了长玻璃纤维(LGF)增强聚甲醛(POM)复合材料。通过6因素2水平的正交试验,探讨了注射压力、注射速度、模具温度、保压压力、保压时间、冷却时间等工艺条件对LGF增强POM复合材料的制品表观和拉伸强度的影响。结果表明:注射压力、注射速度、保压时间和模具温度等4个工艺条件对LGF增强POM制品表观和拉伸强度的影响最大,当注塑成型条件分别为料筒温度180¹90℃、注射压力60 MPa、注射速度60 mm/s、模具温度80℃、保压时间15 s时,制品具有最佳的表观和力学性能。     

Morphological development during injection molding of self‐reinforcing composites. II: Numerical simulations and analytical predictions

In this study, combined numerical simulation of injection molding and analytical calculations have been used to determine the velocity and elongational strain in the advancing melt front (AMF) region, during the molding of PET/LCP blends, at various injection molding conditions. A model is proposed that establishes the relationship between the aspect ratio of LCP fibers and elongational strain, based on the assumption of an affine deformation of the LCP domains. This model enables us to predict the processing dependent morphology of injection molded PET/LCP blends. The effect of processing parameters on the morphology development during injection molding were investigated. The studies show that injection speed and mold temperature have significant effects on the morphological development of the blends, compared with the effect of the melt temperature. A good correlation between calculated and scanning electron microscopy results was obtained.     

注射成型工艺对PBT结晶和降解行为的影响

通过采用不同的注射条件,分别考察了熔体温度、模具温度、螺杆转速、注射速率、背压、保压压力、保压时间、滞留时间等多个重要的注射参数对聚对苯二甲酸丁二醇酯(PBT)小型制件降解程度、结晶形态和力学性能的影响。利用偏光显微镜、DSC、黏度计等,着重研究了各注射工艺参数对制件皮层厚度、结晶度、相对分子质量以及断裂伸长率的影响,从而为优化注射成型工艺过程提供依据。结果表明:熔体温度对制件各项性能的影响最为显著,而螺杆转速、背压、保压压力等的影响相对较小;随着熔体温度的提高和滞留时间的延长,PBT的降解程度迅速加剧,相对分子质量急剧下降,从而使制件断裂伸长率严重降低,力学性能变差。     

车用聚酰胺波纹管挤出成型工艺

介绍了车用聚酰胺波纹管挤出成型工艺流程.分析了聚酰胺波纹管质量影响因素,主要包括原材料含水率、烘干时长、成型温度和速度、模具设计等.讲解了挤出模具直径的确定方法,重点是芯模外径的计算公式.综述了波纹管挤出成型的开机步骤和生产时的注意事项,以及气堵撑杆长度与模块数量的对应关系.强调了1.3 mm是最佳的波纹成型机模块游隙...