Experimental Study of the Flow Characteristics of Rubber Compounds in Extruder Screws

Abstract The application of screw extrusion to rubber compounds probably dates back over a century. Rubber extrusion has been an area of industrial importance throughout this period. Technological innovation continues in this area, as may be seen in a recent review by Johnson. However, there have been only a few basic studies on the flow characteristics of rubber screw extruders. Many more extensive investigations on the working of plastics screw extruders have been carried out. The latter researches are summarized in the volumes by Tadmor and Klein and Tadmor and Gogos. The basic mechanisms of flow of plastics in screw extruders were first revealed in experimental studies by Maddock. He fed the screw with pigmented pellets, pulled it from the barrel with the plastic strips in it, which were then unwound and cross-sectioned. There seem to be few such similar published investigations for rubber compounds. We are only familiar with the work of Menges and Lehnen. It is our purpose in the present paper to ini...