MANUFACTURING METHOD OF DIAGONALLY ORIENTED FILM

PROBLEM TO BE SOLVED: To suppress waving-shaped deformation due to diagonally orientation by appropriately setting timing for opening holding by a holding tool at both terminals in a width direction of a diagonally oriented film.SOLUTION: A manufacturing method of a diagonally oriented film has a diagonally orientation process and a heat fixing process. In the heat fixing process, a film is transported by holding both terminals in a width direction of the film respectively with a pair of holding tools 15A and 15B facing the width direction of the film at a finish point of the diagonally orientation process. When a holding opening position of the film of a first holding tool 15A in a preceding side is a first position S1 and a holding opening position of the second holding tool 15B in a delaying side is a second position S2, a line T connecting the first position S1 and the second position S2 is obliquely inclined in the width direction in the heat fixing process, and holding of the film by the second holding tool 15B is opened before the first holding tool 15A so that the second position S2 is in an upstream side in the transportation direction than the first position S1.SELECTED DRAWING: Figure 4 【課題】斜め延伸されたフィルムの幅手方向の両端の把持具による把持を開放するタイミングを適切に設定することにより、斜め延伸に起因する波打ち状の変形を抑える。【解決手段】斜め延伸フィルムの製造方法は、斜め延伸工程と、熱固定工程とを有する。熱固定工程では、斜め延伸工程の終了時点でフィルムの幅手方向に対向する一対の把持具１５Ａ・１５Ｂで、フィルムの幅手方向の両端をそれぞれ把持してフィルムを搬送する。先行側の第１の把持具１５Ａのフィルムの把持開放位置を第１の位置Ｓ１とし、遅延側の第２の把持具１５Ｂのフィルムの把持開放位置を第２の位置Ｓ２としたとき、熱固定工程では、第１の位置Ｓ１と第２の位置Ｓ２とを結ぶ直線Ｔが幅手方向に対して斜めに傾き、かつ、第２の位置Ｓ２が第１の位置Ｓ１よりも搬送方向の上流側となるように、第１の把持具１５Ａよりも先に第２の把持具１５Ｂによるフィルムの把持を開放する。【選択図】図４