| 摘要 |
PURPOSE:To mold a plug body and a cover body in a single mold by a method wherein molten resins are poured into a plug cavity and a cover cavity which are communicated to each other by a narrow gap, and the resins are fused into an integral body at the part of a gap. CONSTITUTION:A flexible synthetic resin having a low melt index is fed under pressure from a nozzle 37 into the plug cavity 45 through sprues 39, 41 and a gate 43, and is passed through the narrow gap 48 between the cavity 45 and the cover cavity 46 to form the plug body 24. Then, a flexible synthetic resin having a high melt index is fed under pressure from a nozzle 38 into the cavity 46 through sprues 40, 42 and a gate 44, and is integrated with the molten synthetic resin fed into the cavity 45, by bringing both the resins at the part of the gap 48. Accordingly, a plug body 24 and the circular disk shaped cover body 26 is obtained wherein the plug body 24 is comprised of a skirt part 22 having an annular rib 21 at the inside periphery of the lower end and an annular covering part 23 extending inwardly at the upper end of the part 22, and the cover body 26 has a grip 25 on its upper surface and is fused integrally to the covering part 23 by a thin wall part 27. |
