Fast-turning single-screw machines in the plastics processing
Tim Pohl, Helmut Potente
Institut fuer Kunststofftechnik
Germany

Keywords: extrusion, high-speed screw, screw design

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While high screw speeds are well established in the field of twin-screw extrusion, they are only rarely used in single-screw extrusion. On the search for new, more efficient extrusion concepts this idea wins however increasingly in meaning. In this paper the possibilities of high screw speeds are investigated. Nowadays the theoretical and the experimental knowledge of the material and heat transport mechanisms in screw machines is far advanced. The substantial theoretical relations are presented regarding high-speed screws. On basis of these relations different concepts are developed, how one can control the mass temperature and the material degregation despite high screw speeds. Finally those concepts are converted into different screw designs. The developed screw geometries are experimentally examined and compared with the theoretical models.