Patent ID: 7341688

Claim:
An improved method for injection molding in a hot runner system including an injection nozzle having a nozzle body,- a nozzle tip, and a valve stem and having an internal flow channel communicating with an injection orifice in a gate insert or mold that, in turn, communicates with a mold cavity,- said valve stem being reciprocable within said orifice to open and block said flow channel, said method comprising: retracting said valve stem from within said orifice and from blocking said flow channel to permit molten material to flow into said mold cavity to fill said cavity; moving said valve stem into said orifice to block said flow channel and said orifice when said cavity has been filled; and withdrawing said valve stem from the orifice of the gate insert or mold while maintaining the blocking position in said flow channel while said molten material is cooling in said cavity.