Heat shrinkable breathable film for cheese packaging

摘要

A heat shrinkable multi-layer packaging film that has a combination of low oxygen transmission and high carbon dioxide transmission. The film comprises a barrier layer that is made with a co-polyamide having a melting temperature of less that 150°C. The film has a hot tensile strength at 85°C of at least 1800 psi in at least one direction and a percent elongation at 85°C of at least 120% in at least one direction. The film exhibits a CO2:O2 transmission ratio of at least 7.0 at 50% relative humidity. The high tensile strength and percent elongation at or about the shrink temperature are required in order to avoid product deformation, and for irregularly shaped products, allows the film to draw into crevices without imploding. The low oxygen, high carbon dioxide transmission is desirable to retard spoilage and extend shelf life of products.