METHOD FOR CHEMICAL FOAMING IN THE PRESENCE OF REINFORCING FILLERS

摘要

The present invention relates to a method for preparing a foamed item, including the following steps: a) heating a composition including, or consisting of, at least one polyamide PA, at least one compound U including at least one urethane function, particularly a polyurethane PU, at least one reinforcing filler, the content of which is no lower than 10 wt% of the total weight of the composition, and a temperature T such that: the compound U directly or indirectly generates CO2, the polyamide is melted, and in particular, such that the composition is injectable; b) injecting or extruding said composition, the injection particularly being injection molding; and c) recovering the foamed item and an expandable granule including, or consisting of, at least one polyamide, at least one compound U, particularly a polyurethane PU, and at least one reinforcing filler, the content of reinforcing filler being no lower than 10 wt% of the total weight of the composition. The invention also relates to the use of such a composition of such a granule, or a foam or foamed item.