Dewatering of water-moist graft rubber

US5817266A · kind A · utility

Assignee

• BASF SE

Inventors

• Norbert Güntherberg · Speyer, DE
• Jurgen Hofmann · Spalt, DE
• Hilmar Ohlig · Kaiserslautern, DE
• Elmar Mailahn · Worms, DE
• Friedrich Seitz · Friedelsheim, DE
• Hermann Gausepohl · Mutterstadt, DE
• Jurgen Koch · Refrath, DE
• Andreas Deckers · Flomborn, DE

Key dates

• Filing date: Oct 24, 1996
• Grant date: Oct 6, 1998
• Expiry date: Oct 24, 2016

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B29C48/04
• WIPO field: Other special machines
• WIPO sector: Mechanical engineering

Abstract

Essentially dry materials are obtained by mechanically dewatering water-moist rubber, prepared by emulsion polymerization and precipitation, to give a compact material having a rubber content of at least 50%, by a process in which the previously dewatered rubber is fed to the feed section of a twin-screw extruder which has screws rotating in the same direction and possesses, in succession in the conveying direction, at least two back-up zones and two associated dewatering orifices, each of which may be provided with a retaining screw, and at least one kneading zone, one devolatilization zone and finally one discharge zone, which may be closed by a die lip, and the water separated off is discharged at the dewatering orifices in liquid form.