Extrusion system
US4828770A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 16, 1987 |
| Grant date | May 9, 1989 |
| Priority date | — |
| Expiry date | Oct 16, 2007 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C2948/92923
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
Apparatus for extruding a pliable, thin-walled tube comprising an extrusion and shaping die assembly comprising an annular die body, a mandrel supported within the annular die body, a mandrel extension mounted on the mandrel adjacent the die outlet, the mandrel extension having a diameter less than the diameter of the mandrel, a sizing disk supported by the mandrel extension, and a source capable of supplying molten polymeric material to the die assembly under pressure to force the material through an annular extrusion flow channel around the mandrel and out the die outlet thereby forming a moving tube of the material, the mandrel extension extending outwardly from the die in the direction in which the tube is extruded, the annular die body having at least one fluid passageway to channel fluid introduced under pressure into the annular die body axially through the mandrel and outwardly from the axis of the mandrel extension to form an air pillow adapted to cool and support the tube around and spaced from the mandrel extension, and the sizing disk being adapted to restrict escape of the fluid and to define a chamber in cooperation with the tube of the molten polymeric material for c…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.