COMPARISON OF SCREW EXTRUSION OF RUBBER COMPOUNDS WITH DIFFERENT EXTRUDER/SCREW COMBINATIONS

The authors describe a fundamental study of flow mechanisms in screw extruders for rubber compounds. They expand their earlier studies based on the Maddock screw-pulling procedure, with rubber strips containing markers in a comparison of three different screw extruders. The placement of the rubber is recorded and the rubber sections examined for their flow patterns. This work also extends their earlier market experiments on flow of rubber compounds through dies. Their results on screw extruders exhibited both transverse flow patterns and sometimes showed a starved, partially filled screw. Their efforts in this paper seek to generalize these results. They also describe a theoretical model for the flow of rubber compounds in a screw extruder and compare it with their experiments.