PROCESS FOR EXTRUSION OF PLASTIC MATERIAL AND EXTRUSION SCREW FOR THE EXECUTION OF THE SAME

摘要

An extrusion machine (10) includes a barrel or cylinder (14) which houses an extrusion screw (16). The screw (16) includes a feed section (20) into which powder material is fed. The material is then fed into a mixing section (22), then through a transition section (24) and then to another mixing section (26) and finally to a section (28) for mixing and metering the material as it is fed to the die. The extrusion screw (16) in each of the mixing sections (22,28) includes a double flight for causing the material to move back and forth in each section as it is fed to the discharge end of the barrel. The mix and meter section (28) also includes keys (30,32) to further mix the material. IMAGE