Continuous extrusion and tensile strength of self-reinforced HDPE/UHMWPE sheet

A specially designed fish-tail shaped extrusion die was used to continuously extrude self-reinforcing sheet of HDPE/UHMWPE. The result indicated that under conventional extrusion conditions, the tensile strength of extruded sheet was comparable to conventional molded HDPE samples and was almost the same in both MD (machine direction) and TD (transverse direction) directions. While at temperatures slightly above the melting point of HDPE, compared with conventionally extruded sheet, above 6-fold and 3-fold improvements were obtained in the MD and TD direction for HDPE/UHMWPE (I) system in the optimum extrusion windows of 15-30 MPa extrusion pressure, the die temperature ranging from 126 degrees C to 137 degrees C and a rotation speed of 15 rpm. For HDPE/UHMWPE (III) system, in the optimum processing windows, that is, 15-30 MPa extrusion pressure, 131-139 degrees C die temperature and 15 rpm extruder rotation speed, about 5-fold and 2-3-fold improvements were obtained in the MD and TD direction compared with conventionally extruded sheet, respectively. (C) 2007 Elsevier B.V. All rights reserved.