Process for preparing tubular film of hydrolyzed ethylene-vinyl acetate copolymer
US4164529A · kind A · utility
6Cited by
4References
4Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Oct 4, 1977 |
| Grant date | Aug 14, 1979 |
| Priority date | — |
| Expiry date | Oct 4, 1997 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C48/0019
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
In a typical tubular extrusion of hydrolyzed ethylene-vinyl acetate copolymer having an ethylene content of 15 to 50% by mole and a degree of hydrolysis in the vinyl acetate units of not less than 90% by mole, an improved process for preparing the tubular film without wrinkle by controlling the surface temperature of the tubular film at the nip rolls within the range of 50.degree. to 100.degree. C.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.