木塑复合材料注射成型的研究进展

介绍了木塑复合材料注射成型的发展历史及现状,从原料选择和注射工艺两方面对木塑复合材料注射成型的研究进展作了评述。指出在木塑制品的成型方法中,模压法效率低,挤出法产品类型单一,而注塑法成型周期短、花色品种多、制品形状形态各异,因此注塑法在木塑制品成型中的应用将越来越广泛。     

聚甲醛的成型加工

介绍聚甲醛（POM）的成型条件与性能的关系,着重阐述了POM挤出成型、注射成型的基本条件,以及注射成型中常见的制品缺陷及其解决措施等。     

塑料加工成型技术现状及研究进展

综述了塑料加工成型技术的现状及研究进展。通过优化模压成型工艺参数,提高了制品性能并降低了生产成本;共挤成型技术可生产用单一挤出成型技术无法实现的性能优良的制品;注射成型在顺利成型的情况下,应尽量采用较小的注射压力;吹塑成型可成型性能好且具有复杂起伏曲线的制品;发泡成型以生产高质量的发泡制品为目标。塑料加工成型过程中,最大限度地提高能量转化效率是未来研究的主要发展方向。     

国外塑料注射成型新工艺简介

塑料注射成型源于机械制造业中的金属压铸。自从二十年代中期美国制造出第一台塑料注射成型机和欧洲发明了适合于注射成型用的醋酸纤维模塑粉以来,历经半个世纪的变迁,注射成型现已发展成为塑料三大加工方法之一。早在1969年统计注射成型的制品占所有制品的23.9%,仅次于挤出成型占第二位。目前,美国、日本、     

浅析我国塑料成型技术的发展

随着人们对塑料制品品质要求的提高、应用领域的不断扩展，新的塑料制品成型技术不断涌现，本文综述了近年被进一步研发的动态注射成型、流体辅助注射成型(GAIM和WAIM)、微孔发泡注射成型、高速低压注射成型、交变注射成型、熔芯注射成型、旋转成型及反应挤出成型技术，简介了吹塑技术和模压技术的发展，并描述了其各自的特点。塑料制品的成型技术仍有广阔的发展空间，能更进一步地提高制品各种性能、制造成本，并拓宽应用领域。     

PVC／木粉复合材料挤出发泡成型的研究

介绍木塑复合材料挤出发泡成型的发展和加工难点，并针对聚氯乙烯（PVC）／木粉复合材料挤出发泡的成型方法，从原料、配方、工艺、设备等方面作了详细分析。最后简述了PVC／木粉复合材料挤出发泡制品的性能及影响制品性能的主要因紊。     

生物医用高分子材料聚乳酸的成型方法研究

对聚乳酸的一些成型方法作了概述。包括聚乳酸纤维的纺丝成型、自增强成型、泡沫材料的成型。聚乳酸材料的成型可采用注射、挤出、压制等方法，但其制品的力学性能难以满足某些医疗修复器件的要求。经熔融纺丝、自增强成型等特殊成型方法可以获得力学性能较高的制品，聚乳酸泡沫材料可用于组织工程。     

成型收缩和尺寸稳定性专题

随着塑料在精密仪器制造行业,特别是在电子、电器、仪表等行业中的广泛应用,对注射成型制品的尺寸精确性、尺寸随时间的变化等提出了更加严格的要求。塑料成型收缩率既是决定塑料制品尺寸精确性的主要因素,又是影响塑料制品表面精度的关键问题。因此,注射成型塑料制品的收缩问题已经引起人们的高度重视,尤其在精密注射成型过程中必须对塑料成型收缩率进行深入细致的研究。同时,在挤出成型过程中也存在尺寸不稳定的问题,尤其是电线电缆的挤出成型。论坛里面的很多坛友对注射成型塑料制品的成型收缩以及挤出成型塑料制品的尺寸不稳定性问题进行了深入的讨论,现将一部分帖子整理如下,供读者参考。我刊今后将不定期将中塑互联,http://bbs.ourplas.cn上优秀的帖子整理刊发,敬请读者关注。     

我国塑料加工机械的主力——小型注射成型机

塑料注射制品是塑料制品中种类最多的品种，包括大到汽车车身的重量达数十公斤的大型制品，小到重量仅数毫克的用于汽车、信息、医药等工业的微型齿轮。塑料注射成型是塑料加工中最重要的成型工艺，塑料注射成型机成为塑料加工机械中所占比例最高的品种。通常塑料成型机中，注射成型机与挤出成型机的比例为3：1，     

挤出吹塑中空成型工艺参数的多目标优化

以挤出吹塑中空制品品质（制品壁厚分布、制品质量）和生产效率为最终的优化目标，成型工艺参数为设计变量，基于混合人工神经网络和遗传算法建立了挤出吹塑中空成型工艺参数的多目标优化系统。此方法不仅可确定满足实际生产需要的初始成型工艺参数，减少用于确定初始成型工艺参数的时间，而且为挤出吹塑中空成型的工艺参数的确定提供了理论依据，为挤出吹塑中空成型生产的全自动化的实现奠定了基础。     

热塑性聚氨脂过滤器壳制品常见的缺陷及解决方法

介绍了利用热塑性聚氨酯弹性体(TPU)原料制造过滤器壳体注射成型的工艺流程。对生产过滤器壳体制品的缺陷及解决方法进行了深入的分析、总结。列举了过滤器壳体注射成型过程中常见的欠注、流痕、银纹、溢料、制品应力和缩凹变形等缺陷,从影响制品质量的各个因素,如注射成型工艺、模具及产品设计等方面入手,分析其成因并提出了相应的解决方法。     

热塑性聚氨酯与聚氯乙烯共混研究进展

综述了热塑性聚氨酯与聚氯乙烯共混改性研究进展，重点介绍了热塑性聚氨酯与聚氯乙烯共混物的相容性、共混方式、热塑性聚氨酯的类型和组分、助剂和第三组分聚合物等对共混物性能的影响及其应用。     

热塑性聚氨酯透气膜的生产、特点和应用

介绍了热塑性聚氨酯透气膜的生产原料和工艺流程。对两种透湿技术微孔透湿和分子透湿进行了比较 ,并介绍了热塑性聚氨酯透气膜的生产和应用     

聚甲醛的强韧化改性研究

分别以热塑性聚氨酯和短切玻璃纤维为增韧剂和增强剂，以传统的共混方式，对聚甲醛进行了增韧和增强改性研究，获得了强度和韧性同时提高的改性材料。     

Simultaneously improved solid particle erosion resistant and strength of graphene nanoplates/carbon nanotube enhanced thermoplastic polyurethane films

Up to now, it is a major challenge to protect leading edge of the blades from solid particle erosion. Herein, we propose a structure optimization strategy to fabricate non-woven (NW) enhanced thermoplastic polyurethane nanocomposite films (thermoplastic polyurethane [TPU] - NW@G/C_x) with “sandwich - like” structure by hot pressing technology. TPU NW/graphene nanoplates/carbon nanotube (NW@G/C_x) interlayer film were first fabricated by spraying method. Then the interlayer film was laminated between TPU films to fabricate nanocomposite films. Such prepared TPU - NW@G/C_x film shows excellent solid particle erosion resistance and high-tensile strength. For example, the “steel-and-mortar” structure of NW fabric in TPU film results in high-tensile strength of 45 MPa and storage modulus of 21.2 MPa for TPU - NW@G/C_1.0, increasing by 25% and 171% compared with original TPU film (35 MPa, 8 MPa), respectively. In addition, compared with pure TPU film, the “sandwich - like” structure endows TPU - NW@G/C_1.2 with excellent solid particle erosion resistance and the thermal conductivity (0.251 W/m·K). These superior properties extends application of the TPU - NW@G/C_x film on wind turbine blades.     

热塑性聚氨酯基导热纳米复合材料的制备及性能研究进展

简要介绍了本征型和填充型聚合物复合材料的导热机理,从氧化铝、碳纳米管和石墨烯三种导热填料方面,分别概述了这三种填料填充热塑性聚氨酯(TPU)基导热纳米复合材料的制备技术、导热性能及导热机理研究进展情况,论述了每种复合材料在不同填料改性、不同制备技术以及不同填料复合填充条件下带来的导热效率变化,最后对TPU基导热纳米复合材料研究趋势进行了展望。     

SBS/TPU/EVA共混体系三相共连续形态的设计与制备

利用铺展系数法对苯乙烯-丁二烯嵌段共聚物(SBS)/热塑性聚氨酯(TPU)/乙烯-醋酸乙烯共聚物(EVA)三元共混体系的热力学稳定相形态进行预测,以SBS、TPU和EVA为原料,通过转矩流变仪制备了基于三元共连续结构的SBS/TPU/EVA共混材料。研究了各相组分比及加工工艺对三元共混物热力学稳定相形态的影响。结果表明,在转矩加工过程中,TPU倾向于迁移分布在SBS/EVA两相界面处;两组分间的界面张力是否相互匹配是三元共连续结构形成的前提条件;存在最优的组分体积分数比范围,在该范围内得到的三元共连续结构较为完善。     

Study on performance characteristics of fused deposition modeling 3D-printed composites by blending and lamination

Component contacting degree in a composite material is an important reference for evaluation the performance characteristics. In this article, two composite material systems involving polylactic acid (PLA) with acrylonitrile butadiene styrene (ABS) and PLA with thermoplastic polyurethane (TPU) were prepared by blending and laminating through fused deposition modeling (FDM) 3D printing technology. The mechanical and thermal properties of the as-prepared composite materials were examined. The results indicated that PLA and TPU played a dominant role in tensile strength and breaking elongation, respectively, in individual composite material. ABS and TPU changed the glass transition peek, crystallinity, and modulus of PLA. The results also suggested that although the processing design of the blending method was more suitable for the contact between two components, but the mechanical properties of laminated composites were closer to theoretical predictions. The structural design and processing technology provide a comparative method and reference basis for studying the performance characteristics of composite materials.     

Preparation and properties of TPU micro/nanofibers by a laser melt‐electrospinning system

Laser melt electrospinning is a novel technology to fabricate scaffolds in the tissue engineering applications. The melt electrospinning is much safer than the conventional solution electrospinning due to without solvent effect. In this study, thermoplastic polyurethane (TPU) micro/nanofibers were successfully prepared by using this method. The effects of laser current and applied voltage on the fibers morphologies were investigated by scanning electron microscopy. The thermal behaviors and crystallization conditions of the TPU under different states were demonstrated by differential scanning calorimetry and X‐ray diffraction analysis. The mechanical property and the specific surface area of the TPU fibers membranes were also studied. All the analysis results showed that the effects of laser current and applied voltage on the average fiber diameter were complicated, the average fiber diameter ranging from 1.70 to 2.53 µm; the TPU is not an easily crystallized material; the electrospun fibers exhibited an amorphous phase; the average elongation at break laser of the electrospun TPU fiber membranes is about 134%; the average tensile strength is about 1.02 MPa and the specific surface area of the electrospun TPU fiber membrane is about 199 m²/g. POLYM. ENG. SCI., 54:1412–1417, 2014. © 2013 Society of Plastics Engineers     

Experimental investigation of flame retardancy and mechanical properties of APP/EG/TPU multilayer composites prepared by microlayer coextrusion technology

In this paper, ammonium polyphosphate(APP)/expandable graphite(EG)/thermoplastic polyurethane (TPU) composites were prepared by microlayer coextrusion technology, APP and EG fillers had good synergistic flame retardancy and excellent dispersion in TPU matrix, which greatly improved the flame retardancy and mechanical properties of multilayer composites. The dispersion of APP and EG in TPU was characterized by using SEM, the flame retardancy of composites was characterized by using UL94 and LOI, the thermal stability of composites was characterized by using TGA and DTG, and tensile test was used to characterized the mechanical properties of composites. SEM showed that the microlayer coextrusion technology significantly improved the dispersion of APP and EG in TPU. As showed by the experimental results, the vertical combustion level of ordinary blended composites reached V-2 after adding only one kind of filler either APP or EG, and the vertical combustion level of ordinary blended composites reached V-0 with APP and EG applied together, while the vertical combustion level of microlayer coextruded composites all reached V-0 when the total addition of APP and EG was 15%. In particular, the LOI value of microlayer coextruded composites was 30.9%, while the LOI value of ordinary blended composites only was 27.9% when APP: EG = 1: 1. At this time, the flame retardancy level of APP/EG/TPU composites was the best. In addition, the thermal stability and mechanical properties of microlayer coextruded composites were far superior to ordinary blended composites. In conclusion, the synergistic flame retardancy of APP and EG fillers and the dispersion of APP and EG fillers in TPU matrix played a significant role in enhancing flame retardancy and mechanical properties.