Perforated polymeric film with limited oxygen and water permeability
US6296923A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 8, 1994 |
| Grant date | Oct 2, 2001 |
| Priority date | — |
| Expiry date | Jun 8, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31986
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
The invention provides polymeric films for the storage or packing of plant material, the film being perforate and having a water vapor permeability of not more than 800 g m.sup.-2 day.sup.-1 and an oxygen permeability of not more than 200000 cm.sup.3 m.sup.-2 day.sup.-1 atmosphere.sup.-1, both permeabilities being measured at 25.degree. C. with a relative humidity of 75 percent. Examples of polymers which can be used to make the film are regenerated cellulose, homo and copolymers of polyolefins, e.g. with vinyl acetate or methyl acrylate, polyesters and polyamides. Various plant materials, for example carrots, tomatoes, calabrese and mushrooms heat sealed in packs of films of the invention have shown improved shelf lives compared with similar plant materials packaged for example in polyethylene cling film or polyvinyl chloride stretch wrap.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.