European Paulownia Wood for Lightweight Composites

The project at Campus Kuchl of Salzburg University of Applied Sciences reflects ongoing interest in Paulownia wood, a species originally from Asia that has been naturalized in European plantations over the past decade.
Initial research examined sawn wood from Spain, Bulgaria, and Serbia, revealing that properties significantly vary by plantation site. Spanish samples showed higher density and better mechanical traits, while Bulgarian wood, with the widest annual rings, had lower density and mechanical strength.
Further studies assessed the physical and mechanical properties of Paulownia tomentosa x elongata, considering stem height and radial position. Sawn wood from three European sites was evaluated for its suitability in manufacturing solid wood panels, plywood, and particleboards. Serbian samples exhibited better properties from the upper stem and near the bark.
Tests on edged glued solid wood panels (SWP) made of Paulownia, both single-layered and three-layered at 19 mm thickness, used MUF, PUR, and PVAc adhesives. PUR notably enhanced the mechanical properties of the three-layer panels, but their low density prevented them from matching the performance of spruce SWPs.
A study on 16 mm particleboard made with Paulownia at densities of 300 and 400 kg/m³, bonded with UF adhesive, showed that using different particle geometries and high frequency pressing technology, the panels met requirements for LP1 (light) particleboards suitable for general and dry use.
Additionally, research into 7 mm and 15 mm plywood from Paulownia veneers (0.8–3 mm thick) using PUR and MUF adhesives demonstrated that the low-density plywood has strong potential for lightweight construction. Panels with five and seven veneer layers showed particularly promising mechanical properties when bonded with MUF, highlighting Paulownia’s suitability for sustainable, lightweight building materials