快速注塑薄壁制品用PP的结构与性能

Structure and properties of polypropylene for fast injection molded thin-wall products

采用凝胶渗透色谱、差示扫描量热法、偏光显微镜照片及计算机辅助工程(CAE)软件等分析了快速注塑薄壁制品用聚丙烯(PP)K1840的微观结构、宏观性能及其加工性能,并与国外同类产品进行了对比。结果表明:快速注塑薄壁制品用PP K1840分子链结构合理;较高的相对分子质量和适宜的相对分子质量分布使其具有优异流动性的同时保持良好的力学性能;横、纵向成型收缩率均衡,有利于减少制品的翘曲变形。利用CAE软件确定的加工窗口有助于确定PP K1840的注塑加工工艺。

The authors analyzed microstructure, macro-properties and processability of polypropylene（PP） K1840, a grade specially designed for fast injection molded thin-wall product, by means of gel permeation ehromatography（GPC）, differential scanning ealorimetry（DSC）, polarized light mieroscopy（PLM） and Computer Aided Engineering（CAE） software and then, compared the resin＇s characters with those of its overseas counterparts. The results indicate that the molecular chain structure of PP K1840 is rational. The resin＇s high relative molecular mass and its proper distribution contribute to its excellent fluidity as well as good mechanical properties. The balanced longitudinal and transverse shrinkage help to decrease warping of the products. Using CAE software to determine processing window favors the selection of the injection molding parameters of PP K1840.