PREPARATION OF MODIFIED POLYPROPYLENE RESIN COMPOSITION FOAMED BODY

摘要

PROBLEM TO BE SOLVED: To provide a preparation method of a low density polypropylene resin foamed body with uniform internal foams, a high closed-cell rate and a large cross-sectional area. SOLUTION: This modified polypropylene resin composition foamed body is prepared by kneading a mixture of polypropylene resin compositions (modified polypropylene resin compositions) and a foaming agent in an extrusion machine, the polypropylene resin compositions rapidly increasing a stretching viscosity measured in a melt state as degrees of strain increase, retaining the mixture in a cooling mixer controlled at a temperatures suitable for foaming, thereafter extrusion-foaming it in low-pressure ranges.