FIELD: chemistry of polymers. SUBSTANCE: granulate of thermal plastic polymer and talc being preliminary mixed as dry materials are affected by plactication. Into thus prepared plasticized mass gaseous nitrogen and frothing agent are consequently fed, their quantities being 0.1-0.5 mass % and 0.5-5 mass % respectively as calculated for summary mass of said thermal plastic and talc. Alcohol which is chosen of ethanol, isopropanol, 2-methylisopropanol or mixture thereof are used as mentioned above frothing agent. Proposed method is realized in extruder having nozzle for injection of components, distance between points of injection being not less then two diameters of extruder's worm. EFFECT: improves efficiency of the method. 5 cl, 6 tbl, 2 dwg
