| 摘要 |
PURPOSE:To provide a disk molding capable of improving the punched condition of a central opening in the disk molding, and at the same time precluding in advance each member of molds from being troubled such as scuffing or the like, and further having a central opening effectively and usefully. CONSTITUTION:On a stationary side mold 20, a sprue bush 23 is fixed which has a tip end outer periphery for forming the central opening of a disk molding in a manner projecting in the cavity, and on the other hand, on a movable side mold 30, a stationary bush 33 is disposed which has a tip end for forming a gate G for resin material flowing into the cavity between it and the tip end of the sprue bush 23 during mold clamping. Further, on the outside of the stationary bush 33, a sleeve member 34 for opening and closing the gate is provided in a freely advancing and retracting manner. |
