UHMW-PE is a semi-crystalline polymer, it must be sintered by either compression molding (UHMW-PE s UHMW-PE is a semi-crystalline polymer, it must be sintered by either compressionmolding (UHMW-PE sheet) or ram extrusion(UHMW-PE Rod, Pipe, Bar). UHMW-PE Powder, Annealing, prior to machining, helps remove the processing stresses caused by sintering. Finished machined parts can also be annealed, ...