Patent ID: 7198748

Claim:
A method for injection molding foamed molded parts by using a blowing agent in an injection molding unit comprising the steps of: introducing polymer material into an injection molding unit which includes a plasticizing screw movable in axial direction and rotating within a plasticizing cylinder for plasticizing a polymer melt, wherein the plasticizing screw includes a permeable section downstream of a metering zone thereby creating a fluid injection area feed zone, supplying a physical blowing agent to the polymer melt by feeding the blowing agent via a passage in the plasticizing screw to the permeable section and introducing the blowing agent into the melt flow via the fluid injection area feed zone whereby the blowing agent is introduced broadly across the fluid injection area feed zone into the polymer melt in a uniform manner, homogenizing the polymer/blowing agent mixture, injecting the homogenized polymer-blowing agent mixture into a mold.