| 摘要 |
PURPOSE:To provide a method and an apparatus for manufacturing a biaxially- oriented film wherein energy saving, reduction of installation cost, making work easy, making change in design easy and enlargement of an application range of resins which are industrially biaxially drawable simultaneously are realized and reduction of manufacturing cost is attempted and a polyolefin shrink film with no ununiformity in drawing. CONSTITUTION:A cylindrical resin film 11 under molten state being extruded from an extruder 1 through a circular die 2 is cooled to a temp. range wherein the film can be orieneted in a cooling room 5 which is brought into contact with the extrusion side of the die by making the inside and the outer peripheral part of the cylindrical film under the same pressure and feeding a cooling gas, e.g. a compressed air of ordinary temp. Then, while the tension of this film is controlled by means of a tension control roll 6, the cylindrical film is forwarded to a heater 7 at a const. feeding speed and here, the film is drawn by means of a high speed take-up roll 10 while the film is expanded by heating to obtain a biaxially-oriented film 12. |
