A new coating method allows biodegradable plastics to adhere to paperboard, enabling the creation of biopolymer coated packaging suitable for serial production. The technology has been developed in co-operation between Stora Enso, UPM-Kymmene and the Tampere University of Technology, with a view to developing barrier coated paper and board products and packaging solutions, and improving the recyclability of materials.

The first test runs carried out with end customers were done using hot and cold beverage cups, ice-cream cartons and packaging for the fast food sector. Test runs are also currently being made using biodegradable lid material. In principle, nearly all food packaging could be biopolymer coated,according to Stora Enso.

“We have all sorts of opportunities ahead of us now. As a matter of fact, the biggest challenge lies in marketing the innovation”, says Tapani Penttinen, development manager at Stora Enso Packaging Boards. “Biodegradable polymer coating offers a unique alternative, in terms of the environment. The only problematic factor in developing the field is the high price of polylactic acid. We are confident, however, that we will be able to benefit from the price reductions associated with eventual mass production and that legislation will favour packaging which breaks down in the ecocycle”.

Board packaging coated with biodegradable polymers breaks down into biomass and carbon dioxide – the package becomes compost. The actual biopolymer coating is said to turn into compost under appropriate conditions within a few weeks. Estimation of the time frame for the composting process complies with the EN 13432 and DIN 54900 standards, according to which more than 90 per cent of the packaging should degrade into compost within six months.