Plastomer screw extruder - has axial sections of smaller radius of curvature on screw core alternating with much greater radii

摘要

A screw extruder for use in the rubber and plastics industry to plasticize, masticate and mix or homogenize plastic compounds consists of a hollow cylinder in which a screw can turn. The screw has helical ribs on a core which has axial sections of different radii of curvature. The sections are even in number, at least four, and alternate between a radius of curvature up to 15% smaller and a radius of double that of the inside cylinder wall or more. The wedge-shaped gap at the transition from a larger to a smaller radius of curvature exerts a rolling action and increases the plasticizing effect. The area with the smaller radius of curvature applies a shearing stress. A screw extruder of this type can be designed shorter because of the higher throughput rate.