Process for manufacturing films from semi-crystalline fluid polymers by coextrusion and tubular film blowing
US4871506A · kind A · utility
10Cited by
6References
1Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 24, 1987 |
| Grant date | Oct 3, 1989 |
| Priority date | — |
| Expiry date | Dec 24, 2007 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29L2009/00
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A process for manufacturing thermoplastic polymer films by coextrusion comprising coextruding by blow extrusion at least two thermoplastic polymers, one of the polymers being a semi-crystalline fluid polymer, the other a thermoplastic polymer incompatible with and with no adhesive affinity for the semi-crystalline fluid polymer and possessing sufficient extrudate strength to support the semi-crystalline polymer, cooling the coextrudate, separation of the resulting films, and recovering at least the semi-crystalline thermoplastic polymer film thus formed in the form of a film of substantially uniform thickness.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.