PVC

简称    PVC

学名    聚氯乙烯

英文名  polyvinyl chloride

单体    氯乙烯

本色    纯净的聚氯乙烯，只是一种白色的粉未，也就是说它只是一种高分子树脂，不能用于直接加工产品；由于合成工艺路线的不同，这种树脂粉一般分为两类：一种是疏松型树脂，另一种是紧密型树脂。        我们常用的聚氯乙烯胶料都是颗粒状的，它是多组份的塑料，除了前面讲的聚氯乙烯树脂粉以外，还必须加入增塑剂增加它的流动性，加入稳定剂提高它的热稳定性，加入润滑剂提高它的脱模性，以及填料，着色剂，偶联剂等；因为各组份的含量不同，就形成了各种机械性能差异很大的不同硬度的PVC颗粒；它一般用IP度数表示；PVC颗粒大体分为：软质PVC，硬质PVC。外观    因PVC胶料所含的组份不同，它的外观差异很大。有的透明如玻璃，也有不透明的；有的非常柔软，耐折迭，有类橡胶弹性；也有硬质的，象ABS，机械性能优良，可以做工程材料。大部分的PVC有轻微毒性，但不致于一接触就能种毒；也有食品级的PVC胶颗粒。

燃烧特征   PVC难燃，离火即灭；但燃烧时，火焰上端呈黄色，下端呈绿色（绿色是氯离子的特有色谱），冒白色烟雾（白色烟雾是HCL气体与水结合的产物）；燃烧时，胶料发软，同时，发出刺激性的气味，似盐酸。

优点    耐酸碱，不耐有机容剂，电绝缘性优良；有耐火自息性能，这对家电材料相当重要，也比较耐磨，能消声减振；

硬质的PVC：表面硬度，拉伸强度，刚性等机械强度都高于PE，接近于ABS，可以做工程材料。

        软质的PVC，相当柔软，有橡胶弹性，耐折迭

缺点    硬质的PVC，会低温变脆；软质的PVC，会低温变硬。加工过程中，对热敏感，热稳定性差，受热时，引起不同的降解；对硬质PVC，对应变敏感，变形后不能完全复原；对软质PVC，还有增塑剂外迁之敝（增塑剂外迁，引起材料变硬）；因为在加工过程中，多多少少会少量分解HCL气体，它会对设备和模具形成较大的腐蚀，因此，要注意防腐。

用途    用于挤出包装薄膜，农业薄膜，管道，门窗，板材

        用于注塑低档日用品及外壳，非承载荷构件，电线，电缆，插头，减振垫

        用于挤出吹塑容器，中空制品，瓶子

注塑性能   PVC为无定形高聚物，没有明显的熔点，一般加热到120℃--145℃就能熔化，但150℃以下就能分解出HCL气体；180℃就大量的分解成HCL气体；因此，需加入大量的热稳定剂才能注塑，注塑温度的可调区间较小。注塑时，一般使用温度为140℃--160℃；有时也可以达到190℃，但时间不能超过20分钟，否则会大量分解。因为氯离子的存在，它会轻微吸水，生产时，需哄干；烘干温度在75℃--90℃之间，烘干1.5hr—2.5hr；聚氯乙烯的熔体粘度大，流长比小，薄壁制品可能缺胶，因此，浇口和流道相对较大。收缩率为4‰；溢边值为0.05
PVC polyvinyl chloride PVC PVC name English name for short natural Pure PVC for vinyl chloride monomer, is a white powder, that is to say it is a polymer resin, cannot be used for direct processing of products due to the different synthesis routes, which paint is generally pided into two categories: one is loose-type resin, another is close-type resin. We common of PVC rubber material are is particles-like of, it is more group copies of plastic, except front told of PVC resin powder yiwai, also must joined plasticizer increased it of liquidity, joined stable agent improve it of hot stability, joined lubricant improve it of release sex, and filler, coloring agent, I joint agent,; because the group copies of content different, on formed has various mechanical performance differences is big of different hardness of PVC particles; it General with IP degrees said; PVC granules can be pided into: soft PVC, rigid PVC. Look for PVC plastic material the group is different, it looks very different. Some transparent like glass, opaque, some very soft, resistant to folding, with rubber elastic; hard, like ABS, good mechanical properties and engineering materials can be done. Most of the PVC is slightly toxic, but not to the species in a single contact with HIV; also has a food grade PVC plastic granules. Combustion characteristics of PVC fire resistant and fire that destroyed; but when burning, flame top is yellow and the lower green (green is unique to chloride ion chromatography), take the white smoke (white smoke is the product of HCL gas combines with water), burning, soft rubber compound, meanwhile, issued a pungent smell like hydrochloric acid. Advantages of acid and alkali, no organic agents, excellent electrical insulation; interest with heat-resistant properties, which are important to appliance materials, wear-resistant, noise damping;         Rigid PVC: surface hardness, tensile strength, rigidity, mechanical strength is higher than PE, similar to ABS, engineering materials can be done. Soft PVC, soft, elastic, rigid PVC fold disadvantage, low temperature embrittlement; soft PVC will harden at low temperature. Processing process in the, on hot sensitive, hot stability poor, heated Shi, caused different of degradation; on hard quality PVC, on strain sensitive, deformation Hou cannot completely recovery; on soft quality PVC, also has plasticizer relocation of our (plasticizer relocation, caused material variable hard); because in processing process in the, more or less will few decomposition HCL gas, it will on equipment and mold formed larger of corrosion, so, to note anti-corrosion. Uses for extrusion packaging film, agricultural film, pipeline, doors and Windows, plate for injection low-grade commodity and the shell, non-hosted load component, wire, cable, plug, reduction vibration pad for extrusion blow plastic container, hollow products, bottle injection performance PVC for amorphous shaped polymer, no obviously of melting point, General heating to 120 ℃--145 ℃ on can melting, but 150...