| 摘要 |
PURPOSE:To shorten the time of molding for a plastic film by a method in which heating or cooling time is shortened by reducing the heat capacity of any one of an upper molding tool and a lower molding tool in which a plastic film is molded while being heated. CONSTITUTION:A plastic film 1 to be molded is put between an upper molding tool 2 and a lower molding tool 3 made of a thin stainless steel having a small heat capacity. On the back side of the lower molding tool 3, a spiral coil 4 for inductive heating is attached with the aid of an electrically insulating adhesive 5, and water is flowed in the inside of the spiral coil for cooling. After setting the plastic film, a high-frequency current is flowed from a high-frequency heater 8 to the spiral coil 4, wheteupon the temperature of the lower molding tool 3 is quickly raised because of its small heat capacity and thereby the plastic film 1 is softened. Then, the temperature of the tools 2 and 3 is quickly lowered by cooling water and then the film is taken out. In the molding operation, the heating time is 1.5 seconds and the solidification time by cooling is 0.5 seconds. |
