二次开模注射成型微孔发泡PP工艺及其性能研究

Study of Twice-opened Injection Molding Process for Microcellular of Polyprophyhene and Its Properties

介绍了聚丙烯微孔塑料注射成型方法——二次开模成型的原理及工艺。由该方法获得的聚丙烯微孔泡沫塑料有较均匀的泡孔分布,泡孔直径都在20-30／μm,密度大约下降了15％,与未发泡的聚丙烯的力学性能相比,虽拉伸强度下降了24．8％,但缺口冲击强度提高了约125％,弯曲强度提高了19．6％。

A method of injection-moulding for microcellular of polyprophyhene-twice-opening moulding was introduced. The principle and the technology of twice-opening moulding was discussed in detail. The microcellular of polyprophyhene made via this method had uniformly-distributed cells with diameters between 20μm and 30μm. Compared with bulk polyprophyhene, the density of the microcellular foam was reduced about 15 %, the notched impact strength increased by 125 %, the flexural strength increased by 19.6 % at a cost of 24.8 % lowering in the tensile strength.