Polyester films usable for closures and process for their preparation
US5776592A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 3, 1995 |
| Grant date | Jul 7, 1998 |
| Priority date | — |
| Expiry date | Jul 3, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/249921
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
The present invention relates to polyester films which have properties making them suitable for closures, especially of pots for fresh dairy products such as yoghurts, cheeses or desserts. It therefore consists of polyester films which have a thickness of 5 to 30 micrometers and which satisfy the use test, exhibiting a crystallinity higher than or equal to 50%, tensile strengths in the lengthwise direction (MDTS) and in the diagonal directions (.+-.45 degrees relative to the lengthwise direction) (TS45) which are such that: (MDTS)+(TS45).ltoreq.40 kg/mm.sup.2 (392.4 MPa) and elongations at break in the lengthwise direction (MDEB) and in the diagonal directions (.+-.45 degrees relative to the lengthwise direction) (EB45) which are such that: (MDEB)+(EB45).gtoreq.290%. The invention also relates to a process for the preparation of such films and to their use for closures.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.