HEAT-SHRINKABLE TUBE AND ITS MANUFACTURE

摘要

PURPOSE:To prevent the shrinkage in the non-heated state and manufacture a product of high shrinkage factor by providing removably a shrinkage control component for controlling the shrinkage of diameter more than the given level inside the rubber heat-shrinkable tube shrinking in its diameter when heated to the given temperature or over. CONSTITUTION:A shrinkage control component R such as a cross-linking polyethylene tube composed of thermoplastic resin hard at the normal temperature is mounted removably on the outer periphery of a heating mandrel 12. A rubber heat-shrinkable material Wo is overlapped on the outside of the shrinkage control component R in a manner of bonding together. The temperature of the heating mandrel 12 is raised and the shrinkage control component R is heated together with the rubber heat-shrinkable tube material Wo. Then the component is expanded in its diameter to the given dimension, and cool wind is blown to the heated material in the state of being expanded in its diameter to cool and solidify the same. The shrinkage in the radius direction of the rubber heat-shrinkable tube Wo in the non-heated state is prevented perfectly by the shrinkable control component R bonded inside by the arrangement.