MANUFACTURE OF INJECTION MOLDED PRODUCT WITH HOLLOW STRUCTURE

摘要

PURPOSE:To inject smoothly pressurized gas into molten resin in a mold cavity by disposing a check valve in a gas injection opening of a pressurized gas injection nozzle and covering the end of said injection nozzle including a check valve section with the molten resin injection cast into a mold. CONSTITUTION:For instance, polyphenylene ether resin is melted to the resin temperature and plasticized in an injection molding machine cylinder 3 and injection cast into a mold cavity 4, and the end of a gas injection nozzle is covered with a part of molten resin. The injection is stopped after the given several seconds after the start of injection, and simultaneously compressed nitrogen gas metered by a gas meter cylinder 8 out of the injection nozzle is fed forcibly into pressurized gas by a piston 9. A check valve at the end of nozzle is operated effectively and the insulation of the gas injection opening section including the check valve is carried out sufficiently.