A process-development firm is touting the use of liquid crystal polymers as a barrier layer in food packages, instead of traditional ethyl vinyl alcohol. Richard Lusignea, president of Superex Polymer Inc., a Waltham, Mass., firm that does laboratory-scale process testing and development, said the firm has developed a line of multilayer food containers featuring LCPs to provide oxygen and water vapor barriers, while cutting cost and boosting performance.
``We are seeking other companies to help us develop the process on a production-sized basis,'' Lusignea said in a telephone interview. ``We have prototyped the process at the laboratory scale, but have not done a commercial size.''
Lusignea said the first product the company will develop, should partners be found, is a 10-ounce food tray. Shelf life for the product packaged in the tray could be about one year, with a cost reduction of 20 percent over that of EVOH, according to the company's tests. The construction includes an ultrathin layer of LCP between two layers of other sheet material, such as PET or polypropylene.
``Our tests show that in a humid environment the oxygen barrier using LCP is eight times that of EVOH,'' Lusignea said. ``And a layer of less than 0.00040 inch of LCP can do the same job as 0.0020 inch of EVOH. Because you are using less material the cost of the LCP would cost 17 cents per 1,000 square inches, compared with 23 cents per 1,000 square inch.''
The proprietary coextrusion and thermoforming method gives the LCP layer biaxial orientation, and will not require Food & Drug Administration approval.
``We would like to license the process to a manufacturer,'' he said. ``The manufacturer would need a special extrusion die, which we design and build, but the costs would be comparable to conventional thermoformed multilayer cups and trays.''
The company envisions the material for use with microwaved foods, where metal trays are not acceptable. The trays would be able to be heated in conventional ovens if constructed of crystal PET.
Lusignea said prototype trays have been produced for the U.S. military by Superex's affiliated company, Foster-Miller Inc. of Waltham, which required the material to extend shelf life of the packaged product for three years.