聚甲醛成型加工研究进展

Research Progress on Molding Processing of Polyoxymethylene

性能优异的聚甲醛(POM)制品被广泛应用于电子电气、汽车、机械制造、化工、医疗等众多领域,而成型方法决定着其微观结构与宏观性能。首先对国内外现有熔融成型方法中的注塑方法进行陈述,总结分析了成型工艺对微观结构、性能的影响及其在精密微细件的应用情况,并指出注塑方法难以用于制造POM大型制件;阐述了静态模压、烧结成型方法在POM大型制件成型时的优势以及成型效率低等不足之处;最后,分析近几年出现的高速冲击模压成型(HVC)方式在POM成型的研究现状,发现HVC可明显地减少熔融成型常见的收缩、空穴、化学降解等问题,且成型周期短,耗能低,其工业化推广将是未来研究方向之一。

Polyoxymethylene(POM)with excellent performance was widely used in many fields,such as,electronics,automobiles,machinery manufacturing,chemical industry,medical treatment and so on.The molding method determined its microstructure and macroscopic performance.Firstly,the existing injection molding methods of melt molding at home and abroad were reviewed,and the impact of the molding process on the microstructure and performance and their application in precision fine parts were summarized and analyzed.And it was pointed out that the injection molding method was difficult to manufacture large POM parts.Then the advantages of static compression molding and sintering molding methods in forming large-scale POM parts and the disadvantages of lowly molding efficiency were elaborated.Finally,the research status of high-speed impact molding(HVC)in POM molding in recent years was analyzed and it was found that HVC could obviously reduce the common shrinkage,cavity,chemical degradation and other problems of melt molding,and the molding cycle was short and the energy consumption was low.Its industrialization promotion could be one of the future research directions.