Method and apparatus for the manufacture of wear resistant and shock resistant extrudes of ultra-molecular polyethylene

摘要

For producing extrudates from ultra-high molecular weight polyethylene, the cooled feed zone of a single-screw extruder is charged with particulate to powdered polyethylene, which is compressed, melted in a conveying zone of the extruder and discharged with the extrudate being moulded into shape and cooled. In this method, the polyethylene is worked in the conveying zone with a shear rate in the radial clearance between screw shaft and extruder barrel of 50 to 1000 sec-1, is heated to a temperature of 180 to 280 DEG C and is subsequently transferred into a zone without any screw shaft, in which the final moulding of the extrudate takes place.