Method and device for regulating pressure in a single-screw degassing extruder or in a cascade extruder

US7128464B2 · kind B2 · utility

Assignee

• ROEHM GMBH & CO. KG · DE

Inventors

• Bernhard Schaefer · Groß-Gerau, DE
• Michael Meier-Kaiser · Pfungstadt, DE

Key dates

• Filing date: Apr 15, 2002
• Grant date: Oct 31, 2006
• Expiry date: Sep 10, 2022

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B29C2948/92971
• WIPO field: Other special machines
• WIPO sector: Mechanical engineering

Abstract

The invention relates to a method for regulating the minimal value of the pressure in the first half of the metering zone in a direction of conveyance in a single-screw degassing extruder or in a cascade extruder during the conveying of a melt consisting of a thermoplastic. The single-screw degassing extruder or the cascade extruder each have a first screw section (13), a degassing zone (14), a metering zone (22), and a measuring control loop (M), which includes a pressure measuring sensor (P) in the first half of the metering zone, a regulator (R) and an actuator (S) for influencing the pressure in the metering zone. The pressure is measured by the pressure measuring sensor (P) and is set by the regulator (R) and the actuator (S) so that the minimal value at the location of measurement ranges from 0.1 to 10 bar.