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

摘要

The present invention reduces the percentage of defective manufactured moldings by reducing the supply of undesirable gas into the cavity of the mold. The injection molding machine is provided with a heating cylinder (3) for melting a resin material and a resin material supply device (6) for supplying the resin material to the heating cylinder (3). The resin material supply device (6) is provided with: a pump (12) for generating a suction force when driven; a charge hopper (9) into which the resin material is charged as a result of the suction force generated by driving the pump (12); an openable/closeable sealing valve (10) provided on the lower section of the charge hopper (9); and a supply hopper (11) to which resin material charged in the charge hopper (9) is supplied via the sealing valve (10). By driving a vacuum pump (20), resin material is supplied into the heating cylinder (3) with the interior of the supply hopper (11) and the interior of the heating cylinder (3), which communicates with the interior of the supply hopper (11), under vacuum.