| 摘要 |
PURPOSE:To provide a manufacture of Ny 6/MXD 6/Ny 6 biaxially oriented multi-layered film by which excellent forming stability at the time of biaxial orientation can obtained. CONSTITUTION:When the maximum orientation stress in the moving direction (MD) of a film 11 is made sigmaMD and the maximum orientation stress in the width direction (TD) of the film is made sigmaTD, sigmaMD and sigmaTD are set to be 600kg/ cm<2=sigmaTD and sigmaTD<=1600kg/cm<2> respectively. However, it is expressed by the formula of sigmaMD=(FXBMD)/A, F=T/r. Herein, the reference F shows orienting forces, BMD is orientation magnification in the MD direction, A is the cross-sectional area of a raw material film, T is the rotational torque of nip rollers 12, 17, and (r) is the radius of the nip rollers. Also, it is expressed by the formula of sigmaTD=(DELTAPXR)/t. Herein, the reference DELTAP denotes the inner pressure of a bubble 16, R is the radius of the bubble, and (t) is the thickness of the film 11. |
