Ultra strong and flexible wood film could replace plastic
Wood and fibre scientist Qilang Fu and his team at Scion Research have created a transparent wood film that is ultra strong, flexible and has the potential to replace petroleum-based plastics – reducing our reliance on non-degradable polymers in daily life.
The process is simple – a chemical treatment removes lignin/hemicellulose from thin layers of wood that are compressed and dried.
The material becomes 20 times thinner and 25 times stronger than the original wood and mechanically stronger than most materials (strength-to-weight) such as steels, alloys and plastics. Directly derived from wood, it can be produced sustainably and is easily recyclable or biodegradable. The functionality of the material’s surface can be modified by printing or coating, with organic nanoparticles or hydrophobic molecules, for example.
Qiliang Fu says preserving the original orientation of the cellulose fibres gives the translucent wood strength and allows it to be flexible. “Wood is made up of strong and flexible cellulose chains glued together with lignin and hemicelluloses. We wondered if we could remove lignin and hemicellulose but leave the cellulose structures intact – similar to the papermaking process. And could it be made using traditional paper making infrastructure, like a continuous roll-to-roll process, for example”.
“We have actually made a wood-based electronic circuit from the translucent wood and conductive containing carbon fibres derived from lignin as part of a collaboration with my Scion colleague, Dr. Yi Chen,” says Qilang. “This shows the potential for using wood-based flexible electronics in other areas such as wearable devices, smart packaging and sensors.”
“Transparent, flexible wood film could replace petroleum-based plastics and reduce our reliance on non-degradable polymers in our daily life.” The first samples were made with balsa wood. The team is now working on exploring the use of New Zealand-grown wood such as pine and eucalyptus, as well as alternative chemical treatments (e.g. wood bleaching and traditional pulping approaches) to make new transparent wood films.
The wood film was highly commended in the Wood and Fibre Products Technology and Innovation category in the 2020 Resene Timber Design Awards.
The New Zealand Wood Resene Timber Design Awards showcases the innovative, structural and aesthetic use of timber by New Zealand architects and engineers. The event allows engineers, architects, architectural designers and builders to showcase innovation using timber. The Wood and Fibre Products Technology and Innovation category is open to novel wood, wood fibre and derived products or for novel technology and process development, or original application of existing technology and processes.
Related article: A new process for preserving lumber