Abstract: Air is blown on the surface reverse to a cooling drum of the thermoplastic resin film extruded onto the cooling drum. The air is decelerated and is continuously varied in the velocity. An air nozzle to blow air on the surface reverse to a cooling drum of the thermoplastic resin film extruded onto the cooling drum, not less than two air supply openings disposed along the circumferential direction of the drum and a reduction filter covering the air supply openings are provided. The cleaning times of the air nozzle can be reduced, and the thermoplastic resin film is always held in an excellent quality.

Abstract: In a method of drawing a film which comprises drawing the traveling film in the longitudinal direction between rolls and thereafter cooling the drawn film by a cooling roll, the improvement which comprises engaging both side ends or their vicinities of the film with the engaging portions formed on both ends or their vicinities of the cooling roll in the circumferential direction. In the film drawing method of the invention, the drawn film is contacted in a softening state with the cooling roll, and pressed on the surface of the cooling roll by the tension of the film. Thus, both sides of the film are deformed according to the shape of the engaging portions during cooling, and prevent the contraction of the film in the cross direction by the engagement.