METHOD FOR MANUFACTURING HEAT SHRINKABLE TUBE OF THERMOPLASTICITY POLYESTER GROUP

摘要

PURPOSE: A method for manufacturing a heat shrinkable tube is provided to increase a reliability of a product by providing the heat shrinkable tube having an excellent electric property, a heat resistance, a solvent resistance, innoxiousness and a desired shrinkable ratio. CONSTITUTION: A method for manufacturing a heat shrinkable tube is composed of a press out process(10), a cooling process(20), a preheat process(30), a sizing process(40) and a winding process(50). In the press out process(10), a PET(Polyethylene terephthalate) dried resin and a pigment are supplied at a hopper and melted at certain temperature during through passing an extruding machine. In the cooling process(20), the melted resin of a tubular shape having a low viscosity is cooled at a glass transition temperature i.e. 75 °C or less. In the preheat process(30), the tubular shaped resin is preheated at a certain temperature, preferably 60¯100 °C. In the sizing process(40), the tubular shaped resin passes a space having a certain inner diameter, is contacted with a heat medium at a leading end, and extended in a width direction owing to a heat and a cooling at the other end. In the winding process(50), the tubular shaped resin is stretched in a longitude direction.