Monday, March 22, 2010

US Patent 7678841 - Fullerene film with increased gas transmission

Meat is usually packaged in a low-oxygen atmosphere to extend shelf-life. However, the low-oxygen atmosphere creates a discoloration of red meat which can be displeasing when on display at supermarkets. Thus it is useful to form the food packaging with sufficient oxygen permeability so that the meat is not discolored when it reaches the supermarket. This patent from Cryovac teaches providing carbon nanomaterials to improve the oxygen transmission in meat packaging. Claim 1 reads:

1. A method of increasing the gas transmission rate of a packaging film comprising the steps of:

providing a packaging film comprising at least about 0.001 weight %, based on the weight of the film, of fullerene material selected from one or more of spherical fullerenes, bowl-shaped fullerenes, multi-walled carbon nanotubes, carbon nanocones, and carbon nano-onions; and

exposing the packaging film to an amount of radiation energy effective to increase the oxygen transmission rate of the packaging film by at least about 100 cubic centimeters (at standard temperature and pressure) per square meter per day per 1 atmosphere of oxygen pressure differential measured at 0% relative humidity and 23 C.