| 摘要 |
PURPOSE:To prevent the generation of bridge in a vacuum molding by a method in which the portion to be thicker than a specified thickness of a sheet after being vacuum-molded is extended by a clamper when softening the sheet by heating, and the portion to be thinner than the specified thickness is pulled up. CONSTITUTION:The upside of the top force 2 of a vacuum mold 1 is covered with a thermoplastic synthetic resin sheet 12, and its peripheral edge is clamped by clampers 4-11. The sheet 12 is heated to a softening point, the clampers 4-11 are moved, the portion 15 to be thicker than a specified thickness of the sheet after being molded is extended but the portions 13 and 14 to be thinner than the specified thickness are pulled up. The shset 12 is contacted with the top force 2 and subjected to vacuum molding, where immediately before or at the same time as the vacuum suction, the clampers 4-11 are restored to their home positions. |
