| 摘要 |
PURPOSE:To drain gas sufficiently to secure a good fluidity of resin materials and keep off foams getting mixed by providing detecting means which detect the flow-in of resin materials from the cavity of mold into the venting passage and also providing an on-off valve to close the venting passage when the said detecting means detect the flow-in of resin materials. CONSTITUTION:The foaming resin materials P, being injected into the cavity 2 and filled up therein, flow through the gas drainage line 4. When the resin materials come up to the detecting means 5 set up in the said line, the detecting means 5 detect the flow and actuate the closing valve 6 to close the gas drain age line 4. Thus, by draining the gas sufficiently at the time of injection and filling, the fluidity of resin materials P is secured, and the density and yield of molding product are increased by the pressure rise during foaming and harden ing. |
