UHMWPE模压成型方法与技术进展

Progress of UHMWPE Molding Method and Technology

目前,性能较好的超高分子量聚乙烯(UHMWPE)制品得到了广泛应用,但是,由于UHMWPE的黏度较高,难以输送、塑化和成型。模压成型是UHMWPE制品最主要的成型方式之一。首先,对最常用的普通静态模压(CM)成型方法进行陈述,分析并总结了成型温度、成型周期、成型压力以及冷却速率等模压成型参数对CM成型UHMWPE制品微观结构和性能的影响,发现,CM成型存在成型周期长、能耗高以及制品难以兼具良好的力学强度和耐磨性能等问题;其次,阐述了UHMWPE高速冲击(HVC)模压和超声模压的成型原理和特点,发现,引入动态力场后,能降低成型温度、缩短成型周期和减少能耗,但是,由于HVC成型UHMWPE制品韧性较差,超声模压成型制品力学强度较低。因此,动态模压成型方法是UHMWPE制品高效成型的重要研究方向之一。

Ultra-high molecular weight polyethylene(UHMWPE)products with excellent properties are widely used in many industries.However,high viscosity of UHMWPE makes it difficult to convey,plasticize and mold.The compression molding method is one of the most important molding methods of UHMWPE products.The common static compression molding(CM)method,one of the most common molding methods,is stated firstly.The effects of molding process parameters such as molding temperature,molding cycle,molding pressure and cooling rate on the microstructure and properties of static compression molding UHMWPE products are summarized and analyzed.It is pointed out that the static compression molding method has long molding cycle and high energy consumption,and it is difficult to obtain good mechanical strength and wear resistance for its products.Secondly,the UHMWPE molding principle and characteristics of high velocity compaction(HVC)and ultrasonic molding are introduced,and it is concluded that the introduction of dynamic force field can reduce the molding temperature,shorten the molding cycle and reduce the energy consumption.However,toughness of UHMWPE products manufactured by HVC is poor,and mechanical strength of ultrasonic molding products is low.Finally,it is concluded that the dynamic molding method is one of the important research directions of UHMWPE products’efficient molding.