| 摘要 |
PURPOSE:To form a sheet stably at high speed by reducing the electrical resistance of a cooling body, using a specified method at the process in which molten polymer is extruded like a sheet on the surface of an electrostatically changed movable cooling body, and is formed under rapid cooling. CONSTITUTION:A movable cooling body 1 is composed of the cooling roller 3 provided with a insulating film, 4 electrically conductive film 5 and a photoconductive material layer 6 in the discribed order on the surface of said roller. High voltage is applied to between the conductive film 5 and a nozzle 1. From said nozzle 1, molten thermoplastic polymer is extruded on the movable cooling body 11, and then cooled and solidified, whereby polymer sheet 2 may be manufactured (symbol 7 is a separating roller). In the method described above, the portion of the sheet 2 being in contact with the cooling body 11 and at the temperature equal to or higher than glass transition temperature, is irradiated with the light beam from a light source 9, whereby the electrical resistance of the photoconductive material layer is reduced. Consequently, current flows selectively for light irradiated portion, thereby preventing micro electrical discharge having tendency to occur in between the photoconductive film 6 and the sheet 2 immediately before contact with the film 6. Thus, the stable operation at high speed is realized. |
