Patent ID: 6228309
Filing Date: 2001-05-08
Classification: B29C

Abstract:
Process for injection molding, which comprises:injecting melt through a valve gate of a hot runner injection nozzle into a mold cavity;moving a valve stem in said injection nozzle between an open position permitting flow of melt through said gate and a closed position blocking flow of melt through said gate; andholding the valve stem at least at one position between the open and closed positions via an adjustable stop means during flow of said melt through said gate to restrict the flow of melt through said gate;including moving the valve stem between the open and closed positions by a double acting air piston, blocking movement of the valve stem by said stop means, and moving said stop means with a motor means separate from said air piston bidirectionally in relation to said valve stem to set said at least one position at any predetermined position between the open and closed positions.