| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce a deformation amount due to density difference of a molding product.SOLUTION: Operation for injecting melting thermoplastic synthetic resin in a cavity C after mold closing, and then applying dwell pressure, is continued. Then a lower surface of a movable mold 17 and a lower surface of an intermediate piece 15C of a second baseplate 15 are downward dented so that they become gradually lower as going toward their central parts. When the dent amount becomes a predetermined amount, injection operation of the synthetic resin is stopped, a press body 16 is heated for thermal expansion, and with elastic force for returning to an original horizontal state of the dented intermediate piece 15C, the synthetic resin in the cavity C is pressed for enhancing compression density. When the predetermined density is obtained, the heating operation of the press body 16 is stopped, and before stopping the heating operation of the press body 16, cavity forming surfaces of both molds 4, 17 are cooled for curing the synthetic resin. When the synthetic resin is cured enough to be taken out from the cavity C, the press body 16 is cooled and compressed so that it returns to an original state.</p> |
