Solid state extrusion of ultra high molecular weight polyethylene. Processing and properties

The techniques of solid state coextrusion and powder extrusion have been employed for the deformation of ultra high molecular weight polyethylene. Chain folded and chain extended morphologies obtained under different crystallization conditions were coextruded within a nylon 11 casing acting as a processing aid at an extrusion draw ratio (EDR) of 5 at ≤ 120°C and 0.20 GPa. The powder was compacted and extruded at ≤ 128°C and 0.23 GPa up to an EDR of 24. The physical and mechanical properties of the extrudates were evaluated and found to be dependent on intial morphology. An extrudate from the chain‐folded morphology gave a low modulus of 0.71 GPa, the chain‐extended morphology a modulus of 6.7 GPa, and the compacted powder a modulus of 15 GPa.