One end of not yet stretching tube 1 of the thermoplastics which are disconnected in simultaneous biaxial stretching manner

摘要

PURPOSE: To stretch a tube without generating creases or scratches by a method wherein one end of an un-stretched tube is fixed to a tube fixing section of a stretching device and other end is fixed to a slide, and the slide and a movable heating section are moved in the directions separating from each other while air is being injected into the tube so as to expand the tube. ;CONSTITUTION: One end of an un-stretched tube 1 is fixed to a tube fixing section 21 of a stretching device 2 and other end is fixed to a slide 23. A temperature of a heating tank 22b in a movable heating section 22 is set to above a glass transition point and below a melting point of a thermoplastic resin to be used. A temperature of a preheating tank 22a is set to below a set temperature of the heating tank 22b. A pressing air is led into the tube from an air inlet of the tube fixing section 21, the slide 23 is moved in the direction separating from the tube fixing section 21 and the movable heating section 22 is moved in the direction of the tube fixing section 21 so as to biaxially stretch. In this case, the moving speed of the movable heating section 22 is set below the moving speed of the slide 23 so as to keep each speed constant.;COPYRIGHT: (C)1995,JPO