| 摘要 |
PURPOSE:To provide a manufacture of moldings with high rigidity with a hollow part free from deformation. CONSTITUTION:There is used a mold 1 comprising a fixed mold 11 and a movable core 12 reciprocally inserted in the cavity 11 of the fixed mold 11, and a molten synthetic resin 82 is poured into the cavity 111, and subsequently gas 83 is injected into the synthetic resin so as to form a hollow part therein by retreating the movable core 12. In the manufacture of a molding having a hollow part, a recessed groove 121 is provided on the inside surface 120 faced to the hollow part on the movable core 12. Furthermore, while gas 83 is injected into the synthetic resin 82 from the recessed groove 121, the movable core 12 is retreated for forming a hollow part. |
