Apparatus for runnerless injection molding thermosetting materials

摘要

An improved nozzle feed assembly is described. The assembly includes temperature-controlled member, preferably cylindrical in shape, having a closed end and an open end. The open end is fitted with standard threads to facilitate attachment of the nozzle member to the feed barrel of a conventional screw-type molding machine. The nozzle member has an internal temperature controlling means and a plurality of feed outlets positioned on the periphery of the nozzle member near the closed end. The temperature maintained in the nozzle member is sufficiently high to maintain the thermosetting molding material within the nozzle member in a plasticized state and sufficiently low that no substantial curing of the thermosetting molding material takes place. In an alternate mode, the assembly includes a sleeve member positioned around the periphery of the nozzle member and moveable to cover and uncover the feed outlets in the periphery of the nozzle member. In such alternate mode, means are provided to move the sleeve member from a position wherein the feed outlets are covered when the mold faces are open to a position wherein the feed outlets are uncovered when the mold faces are closed.