Side-by-side co-extrusion of film using multiple materials
US4731004A · kind A · utility
34Cited by
32References
13Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Oct 7, 1985 |
| Grant date | Mar 15, 1988 |
| Priority date | — |
| Expiry date | Oct 7, 2005 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29L2007/008
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A film of uniform thickness is formed by two or more materials (A, B, etc.) extruded side-by-side with their common edge joined and co-mingled to form a single piece film. The film is preferably formed in a conventional slot die by use of a barrier dividing the entry manifold into two passages so that the materials co-mingle downstream of the barrier at their common edge. In one application, the film can be extruded partially clear and partially opaque to form a bread wrapper.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.