PURPOSE: To improve traverse stretchability without losing the physical properties of a traverse uniaxially streched film, by stretching a thick film to a traverse axis direction after lightly rolling the same to a longitudinal axis direction in a solid phase state.
CONSTITUTION: It is necessary that a thick film is subjected to rolling treatment to reduce and uniformize the thickness thereof and rolling magnification is set to a range of 1.1W2.5. If the rolling magnification is smaller than said range, rolling effect is hardly recognized and, contrarily, when larger than said range, the longitudinal tearing property of a film becomes remarkable. Therefore, it is necessary that the rolling magnification by a roll is set to 2.5 or less and, at the same time, traverse uniaxial stretching magnification is set to 4 or more. By preliminarily applying light rolling in a longitudinal direction as mentioned above, traverse uniaxial stretching treatment can be drastically stabilized and facilitated.
KIMURA MASATO
TAKAHASHI HOUKOU
| JP36000093A | ||||
| JPS55107427A | 1980-08-18 |