Henkel and Covestro are joining forces to foster sustainability for adhesives in load bearing timber construction. Such elements, as cross-laminated timber (CLT) or glued laminated timber (GLT), are found in a variety of indoor and outdoor applications of buildings, from staircases to facades to structural elements. Covestro is providing Henkel with polyurethane-based raw materials linked to bio-based feedstocks attributed via the mass balance approach. Henkel in turn uses the supplied products for its high-performance adhesive solutions.

"Collaborations along the value chain with like-minded partners are key to enable a circular and climate neutral world. Materials play an important role for example in reducing the carbon footprint of buildings. With Henkel’s new wood adhesive based on Covestro’s ever more sustainable raw materials, we jointly contribute to the circular transformation of the construction industry", said Dr. Thomas Roemer, head of the Coatings and Adhesives business entity at Covestro. 

By enabling timber construction, load-bearing adhesives already contribute to sustainability of building structures. Since timber is a natural material, its properties inherently underly bigger variations than most synthetically produced materials. For example, it is prone to deformation, inhibiting aesthetics as well as functionality, usually limiting its use in load-bearing or other demanding applications. The solution: Utilizing technologies and processes to bond different layers of wood, like cross-lamination or glue-lamination with polyurethane adhesives. Thereby it is possible to create wood panels that maintain strength, form, and functionality over time. By increasing the use of alternative raw materials, the carbon footprint of such material can further be improved.

Dr. Claudia Meckel, head of Product Development Engineered Wood at Henkel, explained, "This is another step towards an ever more sustainable and circular future. Thanks to our work with Covestro, we are able to supply two of our best-selling polyurethane adhesives now being manufactured using alternative raw materials. In addition and by using the mass balance approach, there is no change in product performance and all load bearing certificates of the adhesives remain. With this, we provide our direct customers as well as architects and construction companies with a solution that contributes to their aim of reducing the impact of materials on the overall carbon footprint of buildings." 

Henkel and Covestro both treat sustainability and fostering a circular economy with high priority. For Covestro, broadening its raw material base with bio-based or recycled solutions is key part of that endeavor. Since such alternatives are blended with conventional raw materials in the manufacturing process, segregation and allocation are challenging. To attribute the used alternative feedstock to a final product, the mass balance approach is therefore used. That is a chain of custody method allowing to mix traditional and alternative raw materials during production, but separating and allocating them to products in bookkeeping. The soundness and compliance of this approach is certified externally by the internationally recognized ISCC PLUS scheme. For the wood adhesive, all involved sites and partners of Henkel and Covestro are certified according to this scheme.