To provide a resin molded product excellent in appearance, lightweight properties and rigidity by enhancing the foaming degree of an internal foamed resin covered with a surface layer part comprising a solid resin and avoiding the partial lowering of the rigidity of the surface layer part constituted of a primary hollow molded member.
This molding method of the resin molded product includes a process for molding a parison P from the solid resin, a process for blowing a gas into the molded parison P held in a mold to shape it into a predetermined shape, a process for injecting a foamable resin of a molten state in the obtained hollow molded member in a state that the hollow molded member is left in the mold, and a process for foaming the foamable resin while opening the mold by predetermined quantity after injection to fill the hollow molded member with the resin. The parts X and Y to be stretched of the hollow molded member are preliminarily made thicker than another part in the molding process of the parison P by opening the mold by the predetermined quantity in the filling process.
KANEKO MITSUHARU
ICHIHARA YOHEI
