Production of polyethylene terephthalate film having improved resistance to cleavage
US3980748A · kind A · utility
2Cited by
2References
3Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 18, 1974 |
| Grant date | Sep 14, 1976 |
| Priority date | — |
| Expiry date | Jun 18, 1994 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29D7/00
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A process for the production of a polyethylene terephthalate film characterized by carrying out heat setting after biaxial elongation so that the heat set temperature and heat set time may satisfy the following relations: ______________________________________ heat set temperature 140-213.degree.C. log t .gtoreq. -0.14T + 10.99 heat set temperature 213-223.degree.C. log t .gtoreq. -0.14T + 30.8 heat set temperature 223-255.degree.C. log t .gtoreq. -0.0186T + 3.73 ______________________________________ in which T is a heat set temperature (.degree.C.) and t is a heat set time (min.), and thus obtaining a cleavage-free film.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.