Durable LVL from modified beech wood

Today hardwoods play a minor role in outdoor structural applications. This is due in part to their low durability and poor dimensional stability. For this reason, a collaborative project between the BioEconomy Cluster, the project consortium of Pollmeier Veneer Materials GmbH, the University of Göttingen, and the Fraunhofer IML was undertaken. The project, Continuous Beech, investigated the production of beech veneer lumber for load-bearing outdoor applications.

The aim of the project was to achieve successful chemical-technical modification of beech wood with customized phenolformaldehyde resins. The focus was on reducing water absorption, increasing resistance to wood-destroying organisms and the use of organosolv lignin as a partial substitute for petroleum-based phenolic resins. The modification process of the beech veneer was based on impregnation followed by a specialised drying process and hardening of the modifying chemicals during bonding in a hot press.

The results showed increased dimensional stability and durability of beech wood. Lowering the weight percentage gain (WPG) improved the resource efficiency and weatherability of beech wood. New products and applications for beech wood are now conceivable. However, there is still a need for research. For this reason, the company Pollmeier and the University of Göttingen want to continue working together, for example, to promote a demonstration construction project.