| 摘要 |
PROBLEM TO BE SOLVED: To obtain an acceptable injection molded product of polytrimethylene terephthalate which is a crystalline resin, low in melt flow viscosity, high in rate of contraction by molding and prone to surface sinking. SOLUTION: A method for a gas pressed injection molding which is characterized in that; filling in a cavity of a die by injecting a molten thermoplastic resin composition comprising polytrimethylene terephthalate as the main component, pressing a compressed gas into the cavity between a back side of the molded product and a corresponding cavity surface of the die in a gas press-in area and, push a surface of the molded product against the cavity surface of the die; in the injection molding of the molded product which has a protruded heavy-walled part in its back side. COPYRIGHT: (C)2003,JPO |
