| 摘要 |
PURPOSE:To prevent 'sinkmark' due to shrinkage from developing and consequently contrive to improve the transfer accuracy of a molded item by a method wherein an enclosed space, which is formed on the side opposite to a cavity, of an elastic thin base plate is evacuated so as to deform the thin base plate to the side opposite to the cavity and, after resin is filled in the cavity, the evacuation is released. CONSTITUTION:A thin base plate 2 is deformed to the side opposite to a cavity by being pulled up by the predetermined dimension through the evacuation of an enclosed space 16 in advance from an exhaust port 5 with a vacuum pump. The amount of deformation is the one calculated from the relationship between the cure shrinkage of ultraviolet-curing resin and the molding thickness of resin. Under the condition that a molding equipment is tilted, a valve 10 at the resin exhaust port 15 and a valve 10 at a resin inlet port 14 are opened so as to fill the predetermined amount of acrylic resin from the resin inlet port 14 in the cavity 3. Next, the vacuum pump is stopped and the pressure in the enclosed space 16 is brought back to normal pressure. By actuating a pressing device, the molding equipment is brought back to its horizontal position. Ultraviolet rays are irradiated from an ultraviolet- light irradiation device 13 so as to start the curing of the resin in the cavity 3. As a result, the cured resin shrinks on curing, resulting in restoring the deformation of the thin base plate 2 so as to be turned to a plane, when the resin cures completely. |
