FIELD: production of foamed plastics. SUBSTANCE: method involves plasticizing polystyrene and pore-control substance in extruder followed by introducing into polystyrene melt of 0.2-0.5% by weight of nitrogen as foaming agent; mixing and introducing second foaming agent (partially halogenated compositions) in an amount of 0.5-2% of polystyrene weight and cross-control substance and mixing at 130 C. Extrusion unit for producing foamed polystyrene has hollow cylindrical housing with two injection zones sequentially positioned in the direction of flow of material processed, between which homogenizing auger is positioned. Auger is provided with rotational drive. Distance between injection zones is at least 2D, where D is auger diameter. Injection device for gaseous foaming agent is disposed in the first zone and injection device for liquid foaming agent is disposed in the second zone. EFFECT: increased efficiency in producing foamed material and improved quality of material. 5 cl, 2 dwg
