Self-interference flow of an isotactic polypropylene melt in a cavity during injection molding. II. Morphology and crystallinity

摘要

This article is principally concerned with the morphology and crystallinity of isotactic polypropylene (iPP) parts molded by injection molding, during which a self-interference flow (SIF) occurs for the melt in the cavity. Scanning electron microscopy shows that a transverse flow takes place in SIF samples. Wide-angle X-ray diffraction and differential scanning calorimetry show that SIF moldings exhibit a gamma phase, in addition to alpha and beta phases, and high crystallinity. Meanwhile, the results for iPP moldings made by the conventional flow process, that is, conventional injection molding, are reported for comparison. (C) 2003 Wiley Periodicals, Inc. [References: 27]