The breathable structure strikes a balance between high barrier and permeability to enhance the quality of packed sliced or chunk cheese over the products’ six month shelf life. This semi-permeable characteristic is required because if there is too high a barrier, carbon dioxide can build up, causing packs to balloon. Too little barrier and mold growth can result. This material, a Silver Award winner, also has moisture-barrier properties to prevent cheese from drying out.
According to Alcan associate researcher Jay Hodson, the 3-mil structure is based on a four- or five-layer extrusion lamination of biaxially oriented nylon and oriented polypropylene with EVA sealant. He says a switch to these clear films, which can be printed, is transparent to machinery.
Hodson is unable to identify any end users, only saying that the material was in test by several contract packagers of private-label brands. He expects cheese packaged in the new structure to be on store shelves around late September.
See the story that goes with this sidebar: 2004 DuPont Award Winners
