Hollow-portion-possessing roof rack for use on a motor vehicle and manufacturing method thereof

摘要

A roof rack for use on a motor vehicle, having a hollow portion and comprising a rack body member and leg members on both ends of the rack body member, the rack body member and the leg members being integrally formed, said roof rack being obtained by providing a mold having a cavity for forming the roof rack, a resin injection portion and a pressurized fluid introducing portion, injecting a molten thermoplastic resin into the cavity through the resin injection portion, and introducing a pressurized fluid having a pressure of 20 to 500 kgf/cm<2>-G into the thermoplastic resin in the cavity through the pressurized fluid introducing portion.