| 摘要 |
PURPOSE:To readily mold a resin product having excellent external appearance by forming hollows on both sides of the base part of a rib or the like so that the cooling speed at the base part is made equal to that of the other part in order to prevent generation of sink marks on the surface resulting from the discrepancy between the cooling times of the surface and the interior. CONSTITUTION:A mold 4 is used in which circularly expanded parts 5 encroaching on the molding space S1 for an injection-molded product 1 are formed at the positions corresponding to the positions on both sides of the connecting part of a rib 3 and a slab part 2 on the projecting side of the rib 3. Each expanded part 5 has a large contact area with fused resin, and liberated heat of the interior 2a of the connecting part is radiated through the expanded part 5. Accordingly, the radiation lag due to increase of thickness can be prevented. |
