| 摘要 |
PURPOSE:To reduce neck-in effect or the variability in thickness and obtain a monoaxially orientated film smoothly by a method wherein the film is contacted closely to a rotary cooling drum by employing the method of static electricity impressing cooling. CONSTITUTION:Liquid crystal polymer is extruded out of an extruder so as to obtain the shape of a film and a film, orientated into the flow direction of the polymer, is obtained by employing static electricity impressing cooling method. In this case, a rotary cooling drum, provided with a mirror surface, is arranged immediately below a slit and an air gap is provided. On the other hand, a positive electrode or a tungsten wire, for example, is suspended on the upper surface of the rotary cooling drum orthogonally to the direction of the flow of the film in order to impress an electrostatic charge and, then, a DC voltage is impressed. The amount of extrusion is controlled and the speed of the rotary cooling drum is increased gradually whereby the film is obtained by melting orientation. In this case, the specific resistance of the liquid crystal polymer upon melting is 5X10<8>OMEGA.cm or less and the sectional area of the film after the melting orientation is 1/3-1/100 as compared with the same before the melting orientation. |
