Patent ID: 7293982
Filing Date: 2007-11-13
Classification: B29C

Abstract:
1. A device for an injection molding machine used in the production of foamed plastic molded parts by an injection molding method utilizing a blowing agent comprising: a screw piston supported in an injection cylinder of an injection molding machine defined by a draw-in zone, a compression zone and a metering zone, wherein a diameter of the screw piston downstream following the metering zone is less than a diameter of the screw piston in the metering zone, and mixing elements extending from the screw piston circumferentially and spaced apart in the area of the reduced piston diameter, said mixing elements including end portions from a porous material are loaded with blowing agent, wherein the end portions of the mixing elements discharge the blowing agent into a plasticizing melt in the cylinder through the porous end portions into defined locations proximate the metering zone, and wherein the end portions of the mixing elements terminate proximate a side wall of the cylinder.