MANUFACTURING METHOD FOR BIAXIALLY ORIENTED POLYESTER FILM

• Main Authors: HARUTA MASAYUKI, SUGIMOTO MASANORI, HAMANO AKITO, FURUTA OSAMU
• Format: Patent
• Language: English
• Published: 15.10.2002
• Edition: 7
• Subjects: AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS; PERFORMING OPERATIONS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDEDFOR; SHAPING OR JOINING OF PLASTICS; TRANSPORTING; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL

PROBLEM TO BE SOLVED: To provide a manufacturing method which relates to an effective orientation of a polyester film in a width direction in obtaining a biaxially oriented polyester film with a uniformity of physical property in the width direction by inhibiting a bowing phenomenon when the film is oriented in the width direction. SOLUTION: In the method for manufacturing the biaxially oriented polyester film which is obtained by orienting a substantially non-oriented polyester film in a longer direction and then orienting it in the width direction, the film to be oriented in the width direction is oriented by making its temperature higher at the end part than that in the center in the width direction of the film.