| 摘要 |
PROBLEM TO BE SOLVED: To prevent the surface shape of a hot plate or a mold from being transferred during thermal molding, especially pressure molding by preliminarily heating a thermoplastic resin sheet at a temperature at which the sheet becomes thermally contracted or below, prior to a heating step during thermal molding. SOLUTION: A molding device 1 is equipped with a pressure molding device 2 and a preliminary heating device 3, and a biaxially stretched transparent polystyrenic resin sheet 9 (a thermoplastic resin sheet) is conveyed using a thermoplastic resin sheet conveying device 4. Further, the resin sheet 9 is preliminarily heated at a temperature (80-90 deg.C) at which the resin sheet 9 is not thermally contracted, using heaters 5, 5 in the preliminary heating device 3. Thereafter, the resin sheet 9 is conveyed into the pressure molding device 2 with the help of the thermoplastic resin sheet conveying device 4, and then is placed on a hot plate 6 to be thermally molded. As a result, the surface shape of the hot plate 6 is no longer transferred to the surface of the thermoplastic resin sheet 9 and also the heating time is shortened.
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