Temperature Switchable Membranes for Creating and Maintaining Beneficial Package Atmospheres for Fresh Produce, 1999 Polymers, Laminations & Coatings Conference Proceedings

Raymond Clarke

Director of Product Development

Intellipac Ò Membrane Products

LANDEC CORPORATION

3603 Haven Avenue

Menlo Park, CA 94025-1010

Microporous membranes, coated with side chain crystallizable, (SCC), polymers are currently used as part of a fresh produce bag to provide the permeability to oxygen and carbon dioxide, which the produce needs to continue respiring and maintain quality. The membrane can be used to provide most or all of the requirements of produce, making it suitable for use with impermeable packaging materials or for packing very large quantities, e.g. 1000 lbs. of produce.

The membrane will also increase its permeability to oxygen and carbon dioxide with temperature to supply some or all of the increased respiration needs of produce as the temperature increases. The switch temperature of the membrane can be tailored to occur at any temperature between 0 and 68C. It potentially has applications in areas beyond fresh produce, where a specific gas concentration is needed below one temperature, but is vented above that temperature.