A mandrel-rotating die to produce high-hoop-strength HDPE pipe by self-reinforcement

摘要

This article provides a method to obtain high-hoop-strength high-density polyethylene (HDPE) pipe by mandrel-rotating extrusion. With properly selected processing temperature, pressure, and mandrel-rotating speed, the hoop strength of 90 Mpa has been got. Differential scanning calorimetry and X-ray scattering found the great strength enhancement was owning to high degree of macromolecular orientation in circumferential direction and the shish-kebab structure. (C) 1998 John Wiley & Sons, Inc. [References: 15]