Flat sheet process for production of polyolefin shrink film
US4335069A · kind A · utility
18Cited by
11References
5Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jun 25, 1981 |
| Grant date | Jun 15, 1982 |
| Priority date | — |
| Expiry date | Jun 25, 2001 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C55/146
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A balanced, biaxially oriented polyolefin shrink film is produced using a tenter process by heating the film, stretching the film 7 to 10 times in the transverse direction, cooling the film and then heating and stretching the film 1.5 to 4 times in the longitudinal direction such that the ratio of the transverse stretch to the longitudinal stretch is greater than 2.0.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.