Performance properties of engineered wood composites reinforced by lignosulfonates

摘要

The aim of the study was to investigate the effect of two different types of lignosulfonate (LS1 and LS2) added tourea–formaldehyde adhesive on the performance properties of five-layered plywood panels. The physical properties(density, thickness swelling, water absorption and moisture content), mechanical properties (modulus of rupture,modulus of elasticity and bonding quality) and free formaldehyde emission were evaluated in accordance withinternational standards. The results show that the lignosulfonate used in the production of plywood panelsimproves not only mechanical properties but also physical properties. Furthermore, the reinforcement caused by theuse of proper lignosulfonate resulted in a decrease in free formaldehyde content. Using 3% LS1, eco-friendlyplywood panels with improved physical (max. 22.40%) and mechanical properties (max. 42.40%) and drasticallyreduced free formaldehyde emissions (max. 16.27%) can be produced. It was concluded that lignosulfonates, as abyproduct of the pulping industry, can be used as a high-value additive in formaldehyde-based adhesives forengineered wood composites.