US Patent 7128550 Injection molding machine

An injection molding machine using a two-disk forming mold, in which two disk substrates molded simultaneously are made uniform without unbalance in weight. The injection molding machine uses a two-disk forming mold. The mold includes two disk molding cavities independent of each other, and resin inlets provided correspondingly to the cavities respectively. In the injection molding machine, molten resin is simultaneously injected and charged into the two cavities respectively by two plasticizing/injecting units independent of each other. The operations of the two plasticizing/injecting units are controlled to make the molten resin uniform to be charged into the two cavities.