Throttling means for extruders of the transfermix type

US6206560A · kind A · utility

Inventors

• Paul Meyer · Ascona, CH
• Hans-Dieter Wagner · Bonndorf, DE
• Florian Fischer · Ebersberg, DE

Key dates

• Filing date: Mar 13, 2000
• Grant date: Mar 27, 2001
• Expiry date: Mar 13, 2020

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B29C48/03
• WIPO field: Other special machines
• WIPO sector: Mechanical engineering

Abstract

An extruder of the Transfermix type comprises a barrel in which a screw rotates for transporting and mixing visco-elastic compounds. The extruder has an inlet, a compression section, a plasticizing section and an exit section. The plasticizing section is of the Transfermix type, in which a helical groove in the screw varies in cross section from full area to zero area, while the cross section of an oppositely handed helical groove in the barrel varies from zero to full area. A return section follows the plasticizing section, and the operative contact-surface of the return section is formed by a sleeve which forms a cylindrical gap between the sleeve and the screw, the sleeve being axially movable to close or open the gap to produce a continuously adjustable throttle.