BLOG: Imparting Barrier Properties in Flexible Packaging Application: Part 2
By Deb Bhattacharjee, Adhesives.org Expert Blogger
In an earlier blog HERE, the discussion centered on the fundamentals of barrier properties, how it can be best achieved in a practical and cost effective manner through judicious selection of multilayer polymer films necessary for success in a specific application.While most of the barrier properties to oxygen would come from the plastic layers, design of the polymer backbone in adhesive could also play a very important part in improving the barrier properties. This is quite intriguing as adhesives constitute a very small fraction (~1wt.%) of the total mass of the overall packaging material. The purpose of this blog is to discuss several approaches of improving barrier properties through modification in adhesives composition and incorporation of fillers.
- Acrylic adhesive composition containing (meth) acrylate component and a cure system including naturally occurring filler (e.g. a tannin-containing cellulosic material, such as wood flour) which inhibits free radical cure, and oxygen scavengers like triphenylphosphine and phenyl dihydropyridine, was also reported to impart barrier characteristics in packaging applications (US8231758)
- Epoxy hardener obtained by reacting m-xylylene or p-xylylene diamine with unsaturated carboxylic acid was claimed to have improved gas barrier properties (US20150082747)