Patent ID: 6348171
Filing Date: 2002-02-19
Classification: B29C

Abstract:
A method of controlling nozzle gate drool in a multi-nozzle molding apparatus comprising the steps of:(a) introducing a flow of pressurized melt to a runner passage in a mold for subsequent transfer; (b) transferring said flow of pressurized melt to a plurality of thermally-gated injection molding nozzles via a plurality of secondary melt passages branching from said runner passage; (c) injecting the flow from said nozzles into at least one cavity to perform a molding operation; (d) upon completion of said molding operation, moving a body in said runner passage from a bypass chamber, where pressurized melt is permitted to bypass said body, to a compression zone, where said flow of pressurized melt is at least partially impeded by said body portion; (e) moving said body upstream in said compression zone to create a pressure drop downstream of said body to impede drool at said thermally-gated injection molding nozzles; and (f) opening said mold to eject molded pieces.