A method for producing a foamed blow-molded article, which includes extruding a physical blowing agent-containing foamable molten resin downwardly through a annular die to form a tubular foamed parison, clamping the foamed parison between split molds, and then blow molding it. At the latest before completion of the clamping of the foamed parison between the split molds, a gas is blown toward an inner peripheral surface of an upper portion of the foamed parison, the bottom portion of which has been closed, from a gas ejection outlet located within the foamed parison at a position immediately below the annular die to widen the foamed parison.

A skin-covered foamed molded article having excellent lightweight property, bending rigidity, and favorable dimensional stability, which includes: a skin material composed of a hollow molded body produced by blow-molding an extruded parison; and an expanded bead molded article located inside the skin material, wherein the skin material has an average wall thickness of from 1.0 mm to 5.0 mm, the skin material includes a glass fiber-reinforced polypropylene-based resin containing glass fiber in a range of from 5 mass % to 30 mass %, the glass fiber has a weight-average fiber length of from 0.4 mm to 1.5 mm, the expanded bead molded article includes a polypropylene-based resin, the peeling strength between the skin material and the expanded bead molded article is 0.1 MPa or higher, and the longitudinal linear expansion coefficient of the skin-covered foamed molded article (100) at from 23° C. to 80° C. is 7×10−5/° C. or lower.

A method for producing a foamed particle molded article provided with a skin, includes: forming a hollow molded article; filling a hollow part of the hollow molded article with polypropylene-based resin foamed particles; and heating and fusing the particles to each other. A melt elongation at 190° C. of the polypropylene-based resin forming the hollow molded article is 100 m/min or more. A half-crystallization time at 100° C. of the polypropylene-based resin is between 25 to 80 seconds. In heat flux differential scanning calorimetry, a melting peak temperature of the polypropylene-based resin is between 130 to 155° C., a partial heat of fusion at 140° C. or more of the polypropylene-based resin is between 20 to 50 J/g, and a ratio of the partial heat of fusion of the polypropylene-based resin to the total (partial heat of fusion/total heat of fusion) is between 0.2 to 0.8.

A method for producing a foamed blow-molded article, which includes extruding a physical blowing agent-containing foamable molten resin downwardly through a annular die to form a tubular foamed parison, clamping the foamed parison between split molds, and then blow molding it. At the latest before completion of the clamping of the foamed parison between the split molds, a gas is blown toward an inner peripheral surface of an upper portion of the foamed parison, the bottom portion of which has been closed, from a gas ejection outlet located within the foamed parison at a position immediately below the annular die to widen the foamed parison.

A skin-covered foamed molded article having excellent lightweight property, bending rigidity, and favorable dimensional stability, which includes: a skin material composed of a hollow molded body produced by blow-molding an extruded parison; and an expanded bead molded article located inside the skin material, wherein the skin material has an average wall thickness of from 1.0 mm to 5.0 mm, the skin material includes a glass fiber-reinforced polypropylene-based resin containing glass fiber in a range of from 5 mass % to 30 mass %, the glass fiber has a weight-average fiber length of from 0.4 mm to 1.5 mm, the expanded bead molded article includes a polypropylene-based resin, the peeling strength between the skin material and the expanded bead molded article is 0.1 MPa or higher, and the longitudinal linear expansion coefficient of the skin-covered foamed molded article (100) at from 23 C. to 80 C. is 7105/ C. or lower.

A method for producing a foamed particle molded article provided with a skin, includes: forming a hollow molded article; filling a hollow part of the hollow molded article with polypropylene-based resin foamed particles; and heating and fusing the particles to each other. A melt elongation at 190 C. of the polypropylene-based resin forming the hollow molded article is 100 m/min or more. A half-crystallization time at 100 C. of the polypropylene-based resin is between 25 to 80 seconds. In heat flux differential scanning calorimetry, a melting peak temperature of the polypropylene-based resin is between 130 to 155 C., a partial heat of fusion at 140 C. or more of the polypropylene-based resin is between 20 to 50 J/g, and a ratio of the partial heat of fusion of the polypropylene-based resin to the total (partial heat of fusion/total heat of fusion) is between 0.2 to 0.8.

A method for producing a skin-covered foamed molded article including blow-molding a parison in a mold cavity to form a skin consisting of a hollow molded body, in which the parison is in a softened state by extruding a molten thermoplastic resin, filling expanded beads in the hollow molded body, and heating and fusion bonding the beads by supplying steam via a steam supply pipe inserted into the hollow molded body. The parison is in contact with a protruding portion, formed by protrusion from an inner surface of the mold cavity to an inside of the cavity, forming a recessed portion having a shape corresponding to the protruding portion in the inward direction of the hollow molded body. A steam hole is formed in the recessed portion, a steam supply pipe is inserted into the body, and the expanded beads are heated and fusion bonded by supplying steam.