METHOD FOR PRODUCING PLASTIC FOAMED COMPOSITE

摘要

A foamed article is generally excellent in thermal insulation characteristics, but it is reduced in thermal insulation by the absorption of moisture and is much poor in the strength. Accordingly, there exists a need for a thermally insulating material exhibiting no hygroscopicity and satisfactory strength. A method for producing a plastic foamed composite is provided, wherein a plastic powder or fine particles and polyolefin granules capable of undergoing crosslinking foaming are charged into a mold and are heated with rotation, to thereby form a foamed composite having a surface skin in one process step, which composite is not hygroscopic, has satisfactory strength, and is excellent as a thermal insulator. Further, a method, wherein the surface of polyolefin granules for crosslinking foaming is coated with a material having no or scarce capability for foaming and then the granules are molded, can provide cores comprising foamed granules having a size of, preferably, 5 to 50 mm and being coated with a reinforcing material having a thickness of 0.05 to 0.5 mm, which results in the production of a molded product which is lightweight, has satisfactory strength, and may be deformed but is not broken by a general impact.