Process and system for producing multi-layer extrudate

US5066435A · kind A · utility

Assignee

• Rohm GmbH Chemische Fabrik · DE

Inventors

• Hans Lorenz · Darmstadt, DE
• Heinz Gross · Lutherstadt Eisleben, DE
• Roland Schuchmann · Ober-Ramstadt, DE
• Helmut Haring · Otzberg, DE

Key dates

• Filing date: Mar 5, 1990
• Grant date: Nov 19, 1991
• Expiry date: Mar 5, 2010

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B29C2948/92942
• WIPO field: Other special machines
• WIPO sector: Mechanical engineering

Abstract

For producing a multi-extrudate of thermoplastically processable plastic, a coextrusion adapter block has a multi-part slide having a plurality of side-by-side slide sections mutually spaced in a direction transverse to the flow direction and slidably fitted in the adapter block for movement to adjustably protrude into a secondary runner for adjusting the thickness of a molten extrudate therein. A multi-layer extrudate emerging from the adapter block is further extruded in an extrusion die, and the thickness of at least one layer thereof is measured at a plurality of positions along the width thereof. The width measurements are used to control the positions of corresponding slide sections so that the layer thicknesses can be accurately controlled during an extruding operation.