| 摘要 |
PURPOSE:To mold a film having desired width and thickness, by applying electric field to a melted film that is melted and extruded, and cooling the film by a cooling roller, the intensity of the electric field being changed with the slit of a T-die, the rotational speed of the cooling roller, etc. being kept constant. CONSTITUTION:The melted film 7 of a polyethylene or the like is extruded from the T-die at the tip of an extruder 1, and after electric field is applied from an electrode 6, the film is brought in contact with the cooling roller 5 to be cooled and solidified. At this time, the voltage energized to the electrode 6 and the space between the electrode 6 and the film are varied to change the width of the film to obtain a film having a desired width. EFFECT:The transparency of the film is high and the surface thereof is smooth. |
