Different screw forms can be used according to different needs. Ingeneral, single screw extruder, double wave screw extruder ordouble wave screw extruder are usually used. Only in the productionof special materials, twin-screw extruder is used. However, it issible to fill with calcium carbonate or talcum powder, and toselect single screw or twin-screw extruder. It is called blendingmodification that mechanical method is used to add other polymersinto the polymer to change its properties. The comprehensiveproperties of PP are better than that of PE
PP的介电常数、介质损耗因数都很小，不受频率及温度的影响。PP的介电强度很高，且随温度上升而。这些都是在湿、热环境下对电气绝缘材料有利的。另一方面PP的表面电阻很高，在一些场合使用必须先进行抗静电处理。PP在工业领域和生活消费领域的应用必将得到更为迅猛的发展.PP在我国的销量已一个月大约70万吨左右，目前中国是世界上用量的消费国，随着生活的多姿多彩PP产品越来越多，让消费者感受到科学的优越性
