Patent ID: 7198740
Filing Date: 2007-04-03
Classification: B22D,B29C

Abstract:
1. A method for controlling melt flow in an injection molding apparatus, the injection molding apparatus including a mold block defining a mold cavity and at least partially defining a gate passage to the mold cavity, a manifold and at least one nozzle defining a nozzle melt channel for transferring melt from a melt source to the gate passage, the method comprising: providing a valve pin at the gate passage that is in an open position such that the valve pin is at least partially removed from the gate passage to permit melt flow through the gate passage, wherein the valve pin is positioned outside the nozzle melt channel in the open position; moving the valve pin to a closed position such that the valve pin enters the nozzle melt channel to stop the melt flow to the gate passage; solidifying melt immediately upstream of the valve pin to form a slug to create a seal between the melt source and the gate passage; and removing the valve pin from the nozzle melt channel to return the valve pin to the open position leaving the slug to seal between the melt source and the gate passage.