An extrusion apparatus for processing polymeric material, comprises at least one melting station (2), at least one pumping station (3) arranged operatively downstream of said melting station (2) and arranged to push the molten or softened polymeric material inside an extrusion head and a centrifugation station (4) operatively interposed between the melting station (2) and the pumping station (3), configured to extract any volatile components from the polymeric material.