| 摘要 |
PURPOSE:To prevent the natural shrinkage of a heat-shrinkable vinyl chloride tube during storage at high temperature in the summer season by using an ethylene-vinyl chloride copolymer. CONSTITUTION:An ethylene-vinyl chloride copolymer resin containing 0.3- 10wt% ethylene is extruded into a tube form, and the tube is bridged by irradiation of electron rays, expanded under heating condition, and water-cooled while keeping the expanded state to obtain a heat-shrinkable tube. No natural shrinkage occurs in the ethylene-vinyl chloride tube because of the presence of copolymerized ethylene, although vinyl chloride heat-shrinkable tube suffers natural shrinkage during storage at high temperature in the summer season. |
