高耐压HDPE自增强管挤出系统及试样的结构与性能

本文针对管件在输送压力流体时的特殊应力状态,提出了管材周向自增强的构想,据此设计出了自增强挤出系统.该系统利用芯棒旋转,使大分子链沿管周向取向并在适当的压力、温度条件下生成串晶结构,从而大大提高了管材的周向强度及模量.利用DSC、WAXD和SEM等检测手段对试件的凝聚态结构进行分析,找到了周向强度提高的理论依据.

Extrusion of High Hoop Strength HDPE Tube by Self-reinforcement and the Study of the Structure and Properties of the Sample

This article introduced a new extrusion method to produce HDPE pipes with greatly increased hoop strength. The schematic structure and theory of this extrusion system were discussed. Appropriate melt pressure and temperature fields, in conjunction with rotating mandrel permit the production of PE pipes with high hoop strength and modulus. The morphology of reinforced products has been studied by WAXD, SEM and DSC. The reinforcement is due to the shish kebab structure, which is responsible for the improvement of thermal and mechanical properties. The influence of processing parameter such as melt pressure and speed of mandrel on the strength and modulus of hoop and axis directions has also been investigated. The hoop strength increased with increasing melt pressure and rotating speed of mandrel.