| 摘要 |
PURPOSE:To improve a yield upon a molding process and facilitate the designing of a product and a mold, by a method wherein an air vent port, communicating with a vacuum pump, is provided at the opposite side of the resin casting port of a cavity while the inside of the cavity is evacuated upon molding resin. CONSTITUTION:Resin 4 is poured from the upper side of a resin injecting port 2 upon molding, thereafter, a plunger is descended. When the plunger is descended, the resin is collapsed and spread to the lower part of a pot, then, is extruded to a runner 5. When a vacuum pump 9 is operated in this case, air in a cavity 6 is sucked to the pump 9 through an air vent 7 and an air discharging port 8 whereby the inside of the cavity becomes a condition near a vacuum. The plunger 3 is descended further while keeping this condition, then, the cavity is filled with the resin 4 and molding is finished. According to this method, the faulty molding of a molded product, which is due to cutout or the like, and the poor appearance of the same due to bubbles or the like may be eliminated. |
