New waterproof coating keeps boxes recyclable

Researchers from Queensland University of Technology (QUT) - Albert Tietz and Adjunct Associate Professor Les Edye - have developed a lignin-based waterproof coating to replace the traditional wax coating used on cardboard boxes.

Professor Edye explained that lignin is a naturally occurring by-product from pulped wood and grasses. Using lignin extracted from a commercially grown and processed grass, he said the researchers created a sustainable, waterproof coating.

“Traditional wax coatings are made from petrochemicals and, once it’s on the paper or cardboard, that paper or cardboard can no longer be recycled,” Professor Edye said, noting that around 400,000 tonnes of wax-coated cardboard are added to Australian landfill every year.

“We’ve proven that our lignin coating is cost comparable, is 100% recyclable, provides a high level of waterproofing and strengthens the boxes to a higher degree than wax - not bad for a product made from a renewable resource.”

QUT’s innovation arm - qutbluebox - has been working closely with the researchers for two years, providing more than $250,000 in proof-of-concept funding to develop and scale the coating for industry. The organisation has secured a further $200,000 from private equity firm Black Sheep Capital to optimise the coating’s formula and fund industrial-scale trials, according to its CEO, Michael Finney.

“We’ve already successfully coated the lignin-based formulation on food packaging and prefabricated honeycomb walls used in the construction industry,” Finney said. “We’re now trialling it on fruit boxes for the banana industry.

“Critically, the Black Sheep investment will help us fast-track the waterproof coating’s industrial-scale trialling.”

If the current trial is successful, the researchers anticipate the product will be on the market in mid-2015. Black Sheep Capital Director Daniel Gavel said the coating could be applied “across several marketing sectors - from paper and cardboard to building materials” and the company is confident the product will “deliver a high-value solution to the marketplace”