NOUVEAUX MATERIAUX COMPOSITES ALLEGES, LEURS PROCEDES DE FABRICATION ET LEURS UTILISATIONS.

摘要

The present invention relates to a light composite material consisting of a substrate (15) made of natural fibers and having the structure of felt, wherein: the felt is needle-punched on both surfaces thereof by providing complementary polyethylene fibers; a heat-curable matrix (16) consisting of an aqueous-base resin and an expansion agent is dispersed in the matrix, the expansion of which is initiated by heating same to a given temperature; the weight proportion of the expansion agent in the matrix (16) is between 10% and 15%; and said heat-curable matrix (16) is integrated into the substrate by impregnation. The weight proportions of the substrate (15) and the heat-curable matrix (16) are defined so as to obtain an impregnated substrate having the following weight proportions after a dehumidifying step (12): 10% to 20% of substrate (15) that consists of natural fibers, and 80% to 90% of heat-curable matrix (16).