JPS5698138A - Manufacture of thermoplastic copolimerized sheet - Google Patents

Abstract

PURPOSE:To obtain a sheet of uniform thickness in tight contact with the surface of a cooling body by a method wherein fused thermoplastic copolymer is extruded on the liquid film uniformly stretched on the surface of a cooling body by crushing atomized or dropped liquid which is charged electrostatically, cooled and cured. CONSTITUTION:Fused thermoplastic copolymer 20 extruded from an extruding die 11 is extruded on the surface of a cooling drum 13 which rotates at a constant speed. On the other hand, atomized water particles which are generated from an electrostatical atomization device 14 are supplied onto the surface of the cooling drum 13 and attached thereto. The position is given in front of the position where the copolymer 20 begins to come in contact with the cooling drum 13. The liquid particles attaching onto the surface of the cooling drum 13 are crushed by a rubber roll 15 having a smooth surface to make a thin, smooth liquid film. The liquid is atomized by an electrode 18 and an opposite electrode 19. The fused extrusion material is stretched on the cooling drum 13 through this liquid film, an unstretched sheet 21 of cooled, cured thermoplastic copolymer is accepted through a take-up roll 17 from the surface of the drum 13 and transferred to the following stretching process.