| 摘要 |
PURPOSE:To enable the air and gas entrapped in a reactive resin in a cavity to be surely pushed outside of the cavity from a vent, by performing reactive injection molding in the condition where the temperature of the vent is lower than that of a mold by a specified value, while providing the vent in between the molds with a heat insulating material intervening. CONSTITUTION:The reactive resin which has been injected into the lower part of a cavity 14 is fed into the cavity 14. Then, a part of the reactive resin, the air in the cavity 14 and the gas generated in the foaming are pushed out of a mold 11 from the vent 17 on the upper part of the cavity 14. The mold 11 is heated to 50-60 deg.C by the reaction heat of the reactive resin, but since the vent 17 is fitted onto the mold 11 with heat insulating material 21 intervening, its temperature is lower than that of the mold 11 by 10-20 deg.C. Therefore, even if the vent part 17 is filled with the reactive resin, since the reaction of the reactive resin is delayed than the reaction in the cavity 14, the curing speed is retarded. Accordingly, the air in the cavity 14 and the gas generated in the foaming are surely pushed out through the vent 17. |
