| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing a biaxially oriented crystalline nylon film having no deviation of a thickness, excellent thermal fixability, and excellent printing characteristics or laminating characteristics at the time of postprocessing the film. SOLUTION: The method for manufacturing a biaxially oriented crystalline nylon film comprises the steps of quickly cooling to solidify a melted tubular film discharged from an annular die, then reheating the film, urging the air, and biaxially orienting the simultaneously biaxially oriented film in a no tension state in an MD (moving direction of the film) and a TD (a direction perpendicular to the moving direction of the film). The method further comprises the steps of pre-heat treating the biaxially oriented film at film temperature (80 to 120 deg.C) or higher to a temperature higher by 30 deg.C than this or lower as needed. The method further comprises the steps of introducing the film in a tubular heat treating oven, raising the temperature of the film finally to a temperature lower by 25 to 35 deg.C than a melting point of the crystalline resin by a far infrared radiation heating and hot air from an outside, thermally fixing it, and forcibly air cooling it. |
