NATURALLY SHRINKING TUBE BASED ON POLYURETHANE, AND DEVICE AND METHOD FOR EXTRUSION THEREOF

摘要

PURPOSE: Provided are a naturally shrinking tube based on polyurethane, which can be naturally shrinked owing to volatilization of solvent in a short time, when exposed to air, and a device and a method for extrusion thereof. CONSTITUTION: The naturally shrinking tube is produced by the steps of (i) immersing a polyurethane-based tube in a mixed solvent containing 0-100 wt% of swelling-accelerating solvent, 0-100 wt% of swelling-controlling solvent, and 0-15 wt% of lubricating additive for 1-3 hours, so as to swell the tube, and (ii) exposing the tube to air for 1-4 hours. The tube can substitute a polyvinyl chloride(PVC) which is a existing typical of air-shrinking tube material.