the present invention describes an injection molding process for manufacturing golf balls using thermoplastic materials . the injection mold is provided with a heating source and one or more valve gates . the heating source maintains the temperature of the molten thermoplastic material in the conduits through which it is delivered to the mold cavity , and the valve gate shuts off the flow of molten thermoplastic material to the mold cavity . advantageously , this process reduces or eliminates “ trim ” or waste material , and thus also minimizes the necessity to recycle thermoplastic material .