METHOD OF FORMING INFLATION FILM

摘要

PURPOSE:To rapidly and stably form a film superior in optic properties such as transparency and polish as well as mechanical properties such as antishock strength by a method wherein the film is previously coold by a suction ring and then rapidly cooled by a cooling ring. CONSTITUTION:A bubble 4 extruded from an annular die 1 and being in the molten state is suctioned and inflated by a suction ring 5 to have a larger diameter than a die aperture so as to be previously cooled in a uniform and moderate fashion. Then, the bubble is further inflated by virtue of air pressure in the interior thereof and then rapidly cooled by a cooling ring 7 which blows cooling gas against the bubble opposite to the running direction of the bubble. With this, gases emitted from both suction ring and cooling ring do not interfere with each other, resulting in good bubble capture performance at the suction ring.