| 摘要 |
PURPOSE:To stretch a plurality of thermoplastic resin films while preventing them from being melt-bonded on each other, by stretching the films charged with electricity of prescribed density at the same polarity while overlapping them with each other. CONSTITUTION:A plurality of thermoplastic resin films 2, 2', which are made of polyester, polyamide or the like and have a thickness of 300mu or less, are passed through between two free metal rolls 1, 1' set at the same potential so that the films are charged with electricity of 5X10<-11>-2.7X10<-9>C/cm<2> in density at the same polarity. After that, the films 2, 2' are overlapped with each other while they are electrostatically repulsing each other. The side edges of the films are nipped with clips. The films are stretched in the transverse direction or in the transverse and the longitudinal directions by a tenter process. |
