QUT Waterproof Coating
QUT researchers have developed a new waterproof coating for boxes that is both recyclable and renewable. Photo courtesy QUT

A new waterproof coating for cardboard boxes has been developed in Australia, and it offers significant advantages over traditional wax coatings.

The coating is made from lignin, a naturally occurring by-product from pulped wood and grasses. It was developed by Albert Tietz and Adjunct Associate Professor Les Edye at Queensland University of Technology (QUT).

Not only does it come from a renewable resource, the new coating is recyclable.

"What's most exciting is that our lignin barrier coating is sustainable – 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 explained.

"We've proven that our lignin coating is cost-comparable, is 100 percent 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," the professor added.

The lignin-based coating is currently being trialled on fruit boxes in North Queensland's banana belt. It could also be used on building materials and has already been applied to pre-fabricated honeycomb walls used in the construction industry.

QUT's innovation arm, qutbluebox, has been working with the researchers for two years and has provided more than A$250,000 ($218,000) in proof-of-concept funding to develop and scale the coating for industry.

Work is continuing, and qutbluebox has secured a further A$200,000 ($174,000) from Black Sheep Capital to optimize the coating's formula and to fund industrial-scale trials.

If the trials are successful, the product could be rolled out in mid-2015.