METHOD FOR REMOVING UNDESIRABLE GAS IN INJECTION MOLDING MACHINE AND INJECTION MOLDING MACHINE

摘要

Defective ratio of produced molding parts is reduced by reducing an undesirable gas fed to a cavity of a mold. The injection molding machine comprises a heating cylinder (3) for melting resin material, a resin material feeding apparatus (6) for feeding the resin material to the heating cylinder (3) . The resin material feeding apparatus (6) comprises a pump (12) for generating suction force by drive, a injecting hopper (9) to which the resin material is injected by using suction power generated by driving the pump (12), an openable and closable sealing valve (10) mounted at a lower part of the injecting hopper (9), and a feeding hopper (10) to which the resin material injected to the injecting hopper (9) through the sealing valve (10) is fed. The resin material is fed to the heating cylinder (3) in a state of vacuum of the feeding hopper (11) and the heating cylinder (3) communicated with the feeding hopper (11) by driving the vacuum pump (20).