Researchers at Aalto University in Finland have developed a new method for bonding wood using pulp fibres from Finnish forests. The resulting bond is reportedly twice as strong as natural wood and highly resistant to water. The innovation could help reduce the construction industry’s reliance on fossil-based adhesives.

Engineered wood products, including laminated timber, are gaining popularity as low-carbon alternatives to concrete and steel. However, many of these products still depend on adhesives made from fossil-based chemicals such as phenolics, formaldehyde and isocyanates. As timber construction grows worldwide, the need for biobased bonding solutions is increasing.

Turning Wood’s Natural Structure into a Bonding System

The strength and durability of engineered timber largely depend on the bonding interface, where wood elements connect. Weak or moisture-sensitive bonds can reduce structural performance and shorten a product’s lifespan.

Instead of applying a separate adhesive layer, the researchers used the natural compatibility between wood and cellulose-based pulp fibres. The fibres integrate directly into the wood structure and create a strong interlocking interface.

According to doctoral researcher Shiying Zhang, the approach uses wood’s own structure to form durable connections. By combining wood with forest-derived pulp fibres, the team created a bonding system that becomes part of the material itself. The result is a strong and water-resistant connection without relying on conventional synthetic adhesives.

Supporting More Sustainable Timber Construction

The new technique could support the wider adoption of timber in construction. Replacing fossil-based adhesives with biobased alternatives may improve the environmental profile of engineered wood products. It could also help manufacturers move towards more renewable and circular material systems.

For architects, engineers and timber manufacturers, the development offers a way to improve the performance of timber products while reducing dependence on petrochemical materials. As mass timber construction continues to expand, innovations in wood bonding may play an important role in making building materials more sustainable.

The research was conducted by Shiying Zhang, Professor Lauri Rautkari and Academy Research Fellow Shennan Wang. The findings were published in Nature Communications under the title Multiscale Interface Engineering Enables Strong and Water Resistant Wood Bonding.

Source & photo: Aalto University