| 摘要 |
<p>PURPOSE:To prevent a flaw and a crack from occurring in a synthetic resin plate by the shearing action of an upper mold when the upper mold is lowered by a method wherein in press molding the synthetic resin plate, the synthetic resin plate is placed on a projected part of a lower mold, and thereon a protective metal plate that can be folded at positions corresponding to the corner parts of the projected part is placed. CONSTITUTION:A synthetic resin plate 1 is placed on a projected part 3 of a lower mold 2. Thereon, a protective metal plate 4 is placed. In this state, an upper mold 6 is lowered. The shearing action of lower ends 7a and side faces 7b of the upper mold 6 is received by the protective metal plate 4. The protective metal plate 4 is adaptively folded at hinges 5. In this manner, the synthetic resin plate 1 is not subjected to the shearing action and an excessive tensile force, therefore generating no flawing and cracking. A molded piece having a uniform thickness and a reduced internal stress can be obtained.</p> |
