Process for the production of an ultra-high molecular weight polyethylene film by extrusion

Abstract

Process for producing a film of an ultra-high-molecular-weight polyethylene (UHMW-PE), comprising the steps of providing a UHMW-PE having a density of more than 0.96 g/cm3 and a molecular weight of between 1×104 g/mol and 10×106 g/mol, extruding the provided UHMW-PE with an extruder configured for high shearing, through a combination of a barrier screw with at least one shearing element and at least one mixing element, to give a film, and passing the extruded film over a chill roll combination, with the extrusion temperature being 170° C. to 300° C. The extruded film may be implemented as cast primary film or as film stretched in machine direction. The stretching increases the strengths in machine direction, expands the thickness spectrum and smooths the surface.

Dependencies are inferred from the claim text.