Analysis and Use of Wood Waste in Lithuania for the Development of Engineered Wood Composite

The rational use of wood waste allows the saving of forest resources and contributes to the reduction of the greenhouse effect. Three types of wood waste were used in this work: packaging (W), demolition and furniture construction (PLY), and door production (DW). The work performed an analysis of the granulometric composition of the wood waste and assessed the size, shape, and composition of the wood particles. The particle size was in the range of 0–20 mm, but the quantitative proportion of particles of different sizes in waste of different nature and shape was different. All wood particles were thermochemically treated to reduce the amount of dust and soluble particles and to increase the surface roughness of the wood particles to ensure better adhesion parameters with the binder. The binder used was biopolyurethane. Engineered wood composites (EWC) were formed from biopolyurethane and wood waste in a 50:50 ratio to evaluate compressive and bending strength. The strength values showed that all wastes were suitable for forming composites, but the size of the particles affected the magnitude of these values. The highest compressive stress of 11.7 MPa was obtained from composites using 0–5 mm PLY waste, while the lowest stress of 5.2 MPa was obtained from 0–20 mm W waste. In this case, the size of the wood waste particles affected not only the compressive stress but also the density of the composite. The analysis of the composite densities showed that 84.1% of the variation in the total density values was determined by the sample fraction, particle length-width ratio, angularity and sharpness and 15.9% by other factors that were not evaluated. For flexural strength, particle size and nature did not show a clear tendency, and values ranged from 7.2 to 11.5 MPa. The thermochemical treatment method of the wood particles had no or only a slight effect on the strength characteristics of the engineered wood composite.