| 摘要 |
PURPOSE:To obtain wrinkleless optically unform molding by a method in which the side edge of a thermoplastic resin plate is fixed to a frame having hinged connections and flexible portions, the frame is hung down, the resin plate is heated, and the frame is deformed by shrinkage or expansion according to the shape of the molding. CONSTITUTION:A thermoplastic resin plate 1 is fixed through graspers 3 to a frame 2, the frame 2 is divided into upper and lower sections at the central part, and the upper and lower sections are connected with hinges 5. In fixing the plate 1 to the frame 2, the frame 2 is bent at an adequate angle at the hinges 5, and an external force is applied in the direction of stretching the bend portions of the frames 2 at large angles when forming the resin plate 1 for tensing the plate 1 to prevent the occurrence or wrinkles. |
