Patent ID: 6852264

Claim:
An injection molding method for use with an injection molding machine system characterized by hot or cold runner operable for feeding a liquified plastic molding material to a mold cavity via a manifold, and for maintaining the fluidity of the manifold-resident plastic molding during closure of the injection gate, thereby enabling use of the resident molding material in the following molding cycle, said fluidity maintaining method comprising the steps of: (a) providing a flow path for the liquified plastic molding material extending between a manifold inlet sprue, as fed by the injection machine ram of the system, and a mold cavity fed by a cavity-fill nozzle at the outlet of a runner of the system, (b) providing said flow path as a pre-formed mold component mounted in the manifold and containing a flow conduit of high temperature resistant solid material sized to have self supporting structural integrity for flow conducting the pressurized liquified plastic molding material, and (c) constructing said mold component containing said flow conduit of a non-metallic heat insulation material having a sufficiently low thermal conductivity to heat insulate the liquified plastic molding material resident in the conduit flow path such that this plastic molding material remains at a reasonable uncured molding temperature for the duration of at least one injection cycle of the system due to the heat insulation characteristics of the fluid flow conduit of the system.