Screw-type extruder having a starting valve and throttle

US4984977A · kind A · utility

Assignee

• Werner & Pfleiderer GmbH · DE

Inventors

• Albert Grimminger · Leonberg, DE
• Wolfgang Lauser · Leonberg, DE
• Franz-Josef Müller · Bietigheim-Bissingen, DE
• Gerhard Pfaff · Mainburg, DE
• Edgar Schlipf · Stuttgart, DE

Key dates

• Filing date: Apr 21, 1989
• Grant date: Jan 15, 1991
• Expiry date: Apr 21, 2009

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B29C2948/92904
• WIPO field: Other special machines
• WIPO sector: Mechanical engineering

Abstract

A screw-type extruder has a housing and at least one screw which is rotatably arranged in a bore in the housing and which conveys material while melting or plasticizing in a conveying direction to a discharge channel, a starting valve and a throttle for generating a back pressure on the molten or plasticized material being arranged in the area of the discharge channel. In order to avoid long flow paths of the molten or plasticized material via the throttle and starting valve, there is provided a starting valve/throttle unit having a starting valve and throttle body which is displaceable at right angles to the conveying direction out of a starting position into a throttling position.