Title:
MANUFACTURING METHOD FOR BIAXIALLY ORIENTED FILMS
Document Type and Number:
Japanese Patent JP2021049741
Kind Code:
A
Abstract:
To address the problem of providing a method for manufacturing biaxially oriented film that can predict in advance the occurrence of clip gripping failure in the tenter equipment and reduce such gripping failure and the resulting unevenness in stretching and film cutting over a long period of time.SOLUTION: The method for manufacturing biaxially oriented film comprises, in this order, a longitudinal stretching process in which the sheet is stretched in the longitudinal direction, a transverse stretching process in which the uniaxially oriented film obtained in the longitudinal stretching process is stretched in the width direction by the first tenter device, and a heat fixing process in which the biaxially oriented film obtained in the transverse stretching process is heat treated by the second tenter device. Between the roll located immediately before the entrance of the second tenter unit (Roll A) and the point where the clip of the second tenter unit first grasps the biaxially oriented film obtained in the transverse stretching process (grasping point), the amount of position change in the thickness direction of at least one widthwise edge of the biaxially oriented film obtained in the transverse stretching process is more than 0.00 mm to less than 2.50 mm.SELECTED DRAWING: Figure 4
Inventors:
MOCHIZUKI SHOHEI
FUKUDA SATORU
ICHIMARU TAKEHIRO
FUKUDA SATORU
ICHIMARU TAKEHIRO
Application Number:
JP2019175318A
Publication Date:
April 01, 2021
Filing Date:
September 26, 2019
Export Citation:
Assignee:
TORAY INDUSTRIES
International Classes:
B29C55/14; B29D7/01