MOLDING OF RIM POLYURETHANE

摘要

PROBLEM TO BE SOLVED: To achieve the reduction of the number of processes, the improvement of a molding cycle and the enhancement of the appearance or feel of a molded product by molding RIM polyurethane by a ventless mold having no vent hole and dispensing with various works necessary in such a case that a vent hole is provided to a mold. SOLUTION: The ring part 34 of a core mold 31 equipped with a hollow part 36 and a vent hole 35 is set to the cavity 4 of a mold 1 and the vent hole 35 is positioned at a final material filling part 9. The cavity 4 is reduced in pressure and the hollow part 36 is reduced in pressure from the vent hole 35 and a polyurethane material is injected into the cavity 4 held to reduced pressure from a gate 6 to be foamed and the polyurethane coating of a steering wheel is subjected to RIM molding. The flow leading end part of the polyurethane material flowing to the final material filling part 9 is allowed to flow into the hollow part 36 of the core mold 31 from the vent hole 35.