| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of manufacturing a film roll which has favorable appearance without utilizing oscillation.SOLUTION: A method of manufacturing a film roll includes: (A) a process of continuously supplying thermoplastic resin to an extruder and extruding from a die, and forming a film while traveling; (B) a process of adjusting a film thickness by repeating a step of creating an individual thickness profile by measuring a film thickness during film traveling once at each predetermined interval, a step of creating a measured thickness profile based on one or more individual thickness profiles, and a step of adjusting a lip gap based on the measured thickness profile and a set thickness profile; and (C) a process of winding the film in a roll shape. In the process (B), the film thickness is adjusted so that a degree of a variation (R) of the measured thickness profile per one unit and standard deviation (&sgr;), and an average degree of a variation (R) of integration average profiles calculated by arithmetically averaging the measured thickness profiles per 100 units which are continuously created, and the standard deviation of an average thicknesses (&sgr;) are in predetermined ranges. |
