CHOPPER MIXING SCREW

• Main Authors: SCHIRMER, HENRY, G, SHIDA, MITSUZO
• Format: Patent
• Language: English; French; German
• Published: 13.12.2000
• Edition: 7
• Subjects: AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; MAKING GRANULES OR PREFORMS; PERFORMING OPERATIONS; PREPARATION OR PRETREATMENT OF THE MATERIAL TO BESHAPED; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIALCONTAINING PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDEDFOR; SHAPING OR JOINING OF PLASTICS; TRANSPORTING; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL

An apparatus and process for chopping and mixing a polymeric material having an elongated hollow barrel element with a material inlet end and a material outlet end and housing a rotatable extruder screw. The rotatable extruder screw includes at least one flightless screw section and at least one stationary tube element made from a bearing material and forming a plurality of serrations at at least one end, the stationary tube element being disposed around the flightless screw section within the elongated hollow barrel element and fixed against rotation with respect to the elongated hollow barrel element. The flightless screw section forms at least one material melt recess in a region corresponding to the serrations of the stationary tube element. Extruded products requiring, and characterized by, low shear, uniform dispersive mixing are made in one process step in a single screw extruder employing this invention.