AbstractThe effects of particle size and geometry on the physical (density, water absorption, and thickness swelling), thermal, and mechanical (modulus of elasticity, bending strength, internal bond strength, and screw holding strength) properties of single-layer and three-layer particleboards made from sunflower seed husks were investigated. Panels manufactured from particles with various sizes using a urea-formaldehyde adhesive had densities ranging from 535 to 682 kg/m3. The adhesive ratio was at a level of 16% for the single-layer mat configuration; for the three-layer structure, levels of 14% for the core and 16% for the faces were used, based on the weight of particles. The best results occurred in single-layer particleboard made from fine particles, which nearly met the general purpose requirements of the EN 312 Standard. Determination of the thermal conductivity coefficient demonstrated good insulation properties of all panels and their potential use for different structural configurations which are not subjected to strong stresses, suitable for interior design.