混練ノズルを用いた熱可塑性複合材料の射出成形
Injection Molding of Thermoplastic Composites Using Mixing Nozzle
山田浩二・泊 清隆・浦井茂雄・_田泰以・山本一雄
Yamada, Kohji / Tomari, Kiyotaka / Urai, Shigeo / Hamada, Hiroyuki / Yamamoto, Kazuo
Injection molding of thermoplastic composites, poly (ethylene terephthalate) (PET)/polyethylene (PE) alloy and polycarbonate (PC) /poly (acrylonitrile-butadiene-styrene) (ABS) alloy, was examined with a novel mixing nozzle which was expected to have the capability of plasticizing and mixing these materials and making useful polymer alloys conveniently. The effects of the mixing nozzle were investigated by observing morphology of molded samples using a scanning electron microscope (SEM) and by measuring their mechanical properties, for example, tensile strength and Izod impact strength. Mixing of dry-blended PET/PE, which is an immiscible alloy, was promoted by the high shear effect of the mixing nozzle which gave a homogeneous and fine dispersed particles. The tensile strength of the alloy made by the mixing nozzle was almost the same as that made by a conventional open nozzle. However, elongation at break of the samples molded by the mixing nozzle was several times higher than that by the open nozzle. Though the shear effect of the mixing nozzle was also high in the case of PC/ABS, the narrow and complicated flow path in the mixing nozzle resulted in large pressure loss in the dwell process and the dispersed ABS phase in the alloy was deformed and different from that molded by the open nozzle.
Key words: Injection molding / Mixing nozzle / Poly (ethylene terephthalate) / poly-ethylene alloy / Polycarbonate / poly (acrylonitrile-butadiene-styrene) alloy