Verfahren zum Herstellen eines Verbundschaumstoffgegenstandes

摘要

A composite foamed molded article which is lightweight and has high rigidity is prepared by:- (i) setting a skin material (3) in the vicinity of an upper mold (1) for stamping-mold kept at a temperature of 10 to 50 DEG C; (ii) feeding a molten polypropylene resin composition (4) for a substrate containing a foaming agent kept at a temperature of not lower than a decomposition temperature of the foaming agent and within the range of 180 to 240 DEG C onto a surface of a lower mold (2) for stamping-mold kept at a temperature of 30 to 80 DEG C; steps (i) and (ii) being carried out in either order or simultaneously (iii) closing the upper and lower molds (1, 2) within 10 seconds after feeding of the polypropylene resin composition (4) to clamp the molds (1,2) at a pressure of 20 to 70 kg/cm<2>, thereby to laminate a substrate layer formed from the polypropylene resin composition (4) and the skin material (3) simultaneously with shaping of the substrate; (iv) lifting the upper mold (1) before a thickness of each of hardened layers formed on both surfaces of the polypropylene resin composition (4) layer reaches 1.0 mm to open the upper mold (1) and the lower mold (2) at a distance between these molds of 1.1 to 2 times of a thickness of a flat portion having neither boss nor rib in the polypropylene resin composition layer,thereby to foam the polypropylene resin composition; and (v) cooling the foamed substrate layer made of the polypropylene resin composition (4) to harden the substrate layer.