| 摘要 |
PURPOSE:To prevent a molded item from having a burr, a thin spot or bubbles, by loading a synthetic resin into a cavity of molds with the cavity kept at a vacuum, and closing the cavity after the loading thereby venting being facilitated. CONSTITUTION:A stationary mold 4a of the molds is provided with a bore 16 extending to the cavity 15a, the bore 16 is in communication with a passage 17 leading to a vacuum pump, and a slidable stopper 18 is arranged which can clog the bore 16. Immediately before and during the loading of a melted resin into the cavity 15a, the stopper 18 is retracted from the surface of the civity 15a to cause the cavity to be in communication with the vacuum pump, and immediately before the completion of the loading of the resin, the stopper 18 is advanced to the surface of the cavity to close the cavity 15a. |
