Method for shaping plastic materials

US4689187A · kind A · utility

Assignee

• VEB Kombinat Textima · FR

Inventors

• Kurt Markel · Glauchau, DE
• Werner Berger · Dresden, DE

Key dates

• Filing date: Feb 15, 1985
• Grant date: Aug 25, 1987
• Expiry date: Feb 15, 2005

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B29C2948/92923
• WIPO field: Other special machines
• WIPO sector: Mechanical engineering

Abstract

The invention includes a method and an extrusion apparatus for shaping plastic materials particularly those of high molecular weight, whereby the temperature distribution in an extrusion cylinder allows for the build-up of very high pressures and all axial pressure forces are absorbed by a two-sided extruder screw, the extrusion cylinder and, in some instances, the therein contained plastic material. In practicing the method, the plastic material in a flowing state, and at a positive pressure, is continuously conveyed to an extrusion apparatus, and subsequent to its entrance in an extrusion cylinder and before its discharge is cooled to a temperature below the solidification point, not only from the outside by a cooling source in the extrusion cylinder but also from the inside by a cooling source in the interior of the extruder screw. The present invention makes possible the production of materials of improved strength and elasticity, which can be molded to synthetic threads, films and splittable films.