Inclusion for controlling or modifying the atmosphere in packaging comprising reactive material within a semi-permeable envelope

摘要

The inclusion comprises fill material 18 that reacts with water vapour to generate oxygen, and absorb or generate carbon dioxide, within an envelope 10. The envelope comprises a permeable support layer 12 laminated to a water vapour control layer 14. The water vapour control layer 14 is impermeable to liquid water, but permeable to water vapour and gases, and comprises a 10-20 µm thick polyamide or polyethylene film. The preferred support layer 12 is non-woven polyethylene fabric. Preferably the reactive fill material 18 comprises sodium carbonate peroxyhydrate, calcium bentonite clay or zeolite, sodium chloride, and sodium carbonate or sodium hydrogen carbonate and citric acid. The inclusion is used in modified atmosphere and controlled atmosphere packaging systems, for food.