| 摘要 |
PROBLEM TO BE SOLVED: To prevent the collapse of the hollow part of a molded product by mixing a foaming agent with a molten resin. SOLUTION: When the discharge of high pressure gas is completed, the discharge passage of high pressure gas is closed by a molten resin 3 and the pressure acting on the molten resin 3 lowers to the same degree as atmospheric pressure and, therefore, the foaming agent in the molten resin 3 facing to a hollow part 4 begins to foam and, accompanied by the advance of foaming, the hollow part 4 is gradually filled with a foamed part 9 from the outside thereof to the inside thereof. After the whole of the hollow part 4 is filled with the foamed part 9, the molten resin 3 is solidified to release the mold 1 to obtain a molded product. When the molded product is used as a core material and a skin is molded, the foamed part 9 present in the hollow part is not softened. |
