Barrier materials are important in areas including food packaging, where they protect foods against external influences such as oxygen, moisture, dust and oils, as well as preventing fats, water or inert packaging gases from escaping.
Some foods also require breathable packaging, with a controlled through-flow of specific gases for a long shelf-life. Other types of barrier functions may be functional, such as releasing antimicrobial substances or preventing the transfer of printing ink.
Today's commercial barrier materials tend to originate from petroleum raw materials or be made from various metals. At Innventia, research of barrier materials focuses on renewable alternatives, which are intended to replace petroleum-based materials. The bioplastic formulations we work with include chitosan, alginates, hemicellulose, nanocellulose and proteins such as whey protein and wheat gluten.
Established process methods
In our work to develop new barrier materials and films, we mainly work with well-known, established process methods such as extrusion, dispersion coating, hot pressing and injection moulding. There is always a great emphasis on being able to process the material formulations we develop using the equipment that converters currently have.
When developing new barrier materials, Innventia focuses on renewable materials. The image above shows an oxygen barrier film consisting of chitosan. Chitosan is based on the natural polymer chitin, which is the structural element in the exoskeleton of shellfish and insects.