EXPANSION TUBE HAVING SLIT HOLES FOR HEAT SHRINKABLE TUBE

摘要

PURPOSE: A slit type expansion tube for a heat shrinkable tube is provided to improve elongation by quickly cooling the heat shrinkable tube and reducing friction when expanding the heat shrinkable tube at high speed. CONSTITUTION: In an expansion tube(120) for expanding a heat shrinkable tube in a vacuum chamber, a plurality of latticed slit holes(120a) are formed at the outer circumference of the expansion tube, lengthwise. A plurality of ribs formed between the slit holes are regular in thickness. The slit hole is one to fifteenth to one fifth to the expansion tube in length. The expansion tube uniformly applies vacuum pressure to the surface of the heat shrinkable tube through the slit holes, and stably expands the heat shrinkable tube. The expanded tube is cooled quickly when the heat shrinkable tube is expanded at high speed. A friction between the inner wall of the expansion tube and the outer surface of the expanded tube is reduced.