Life Cycle Assessment of Plywood Using Thermally Modified Birch Veneers Bonded with Suberinic Acids Adhesive

This study evaluates the environmental performance of plywood manufactured from thermally modified birch veneers using the Thermovuoto® process, bonded with a birch bark–derived suberinic acids adhesive. Framed within the context of sustainable materials development and the circular bioeconomy, the research examines the potential of bio-based adhesive systems as alternatives to conventional phenol–formaldehyde resins. A cradle-to-grave life cycle assessment (LCA) was performed, encompassing birch bark harvesting, adhesive production, veneer thermal modification, plywood manufacturing, distribution to the customer, and end-of-life management. Environmental impacts were modelled using openLCA 2.4 in combination with the Ecoinvent 3.11 database, in accordance with ISO 14040 and ISO 14044, applying the ReCiPe 2016 v.1.03 (H) midpoint life cycle impact assessment method. The results indicate that the birch bark extraction stage, particularly ethanol use derived from potato fermentation, constitutes the dominant contributor across all assessed impact categories. Overall, the LCA outcomes suggest that thermally modified, suberinic-acid-bonded birch plywood represents a promising niche bio-based material, with clear potential for further environmental improvement through process optimization.