Abstract: The present invention relates to an apparatus for shrinking volumes of waste foamed plastics which have been used as packing materials. The waste plastic materials are thrown into a hopper provided on a crushing room having an opening in an upper part and tapering towards its lower part. A plurality of crushing vanes having a radius of gyration of length reaching within said hopper rotate in said crushing room, to break the foamed plastics into shreds. The broken plastics flow into a sending cylinder through a receipt opening toward the side wall of the crushing room, and are sent forward by screw vanes within the sending cylinder. Subsequently, the waste plastics are compressed in a compression cylinder connected in series to the sending cylinder and further softened and de-foamed by a heating cylinder and exhausted through a nozzle provided at the end of the housing cylinder. Extruded bar like shrinked resins are cut into chips by a rotating cutter and exhausted from the apparatus by air flow.