The air valve system, which consists of a membrane, a baffle film, and a permanent adhesive, is custom engineered by avery dennison industrial and automotive products and uses venting label valve technology, graphics, and coatings from exopack, spartanburg, sc. When air inside the package expands due to changes in temperature or altitude or is compressed by forced pressure, air will escape through the valve&rsquos membrane until the package&rsquos inside air pressure is equalized. The system protects packaged contents from moisture and contaminants, equalizes air pressure during transit, and improves pallet stacking and stability. In early september, avery dennison announced an expansion of the concept to microwave food packages. The steam release valve uses the same general three component structure. The pasadena, cabased company is also testing another version for use in rigid containers, such as blow molded bottles, where it can equalize the pressure after processes such as hot filling. It will also help prevent the bottle from paneling during shipment at higher elevations. The system has been commercial for about a year in an awardwinning industrial application for cargill for diamond crystal jiffy melt ice melter bags. Greco said the concept supports a broad range of end uses, including the packaging of industrial chemicals, pet foods, building supplies, fertilizers, and fine and coarse grain materials. The air valve is comprised of three components a baffle typically made of polyester film, with a diecut pattern that controls air flow a perforated membrane that filters air into or out of the package and an adhesive to adhere it to the film or package.
