KNEADING DEVICE, METHOD FOR PRODUCING THERMOPLASTIC RESIN MOLDED BODY, AND FOAM INJECTION MOLDING METHOD

摘要

Provided is a device for kneading a thermoplastic resin, the kneading device comprising: a plasticizing cylinder having a high-pressure kneading zone in which a molten resin obtained by plasticizing and melting said thermoplastic resin and a pressurized fluid are brought into contact and kneaded, and a reduced-pressure zone in which the gasified pressurized fluid is exhausted from the molten resin that has been brought into contact and kneaded with the pressurized fluid; a screw arranged inside the plasticizing cylinder in a rotatable and advanceable/retractable manner; a downstream-side seal mechanism provided between the high-pressure kneading zone and the reduced-pressure zone and blocking the communication between the high-pressure kneading zone and the reduced-pressure zone; and a reduced-pressure-zone pressure adjustment mechanism connected to the reduced-pressure zone of the plasticizing cylinder and controlling the pressure in the reduced-pressure zone when the downstream-side seal mechanism has blocked the communication between the high-pressure kneading zone and the reduced-pressure zone, said pressure adjustment mechanism controlling the pressure in the reduced-pressure zone to a pressure higher than or equal to atmospheric pressure and lower than or equal to the maximum pressure in the high-pressure kneading zone reached when the pressurized fluid is brought into contact and kneaded with the molten resin.