Properties of Hybrid Plywood Produced by Utilisation of Peeler Cores

The aim of this research work was to investigate the feasibility of upcycling poplar (Populus spp.) peeler cores as a by-product from the production of plywood in manufacturing lightweight hybrid poplar and beech plywood panels, containing different ratios (60%, 80%, and 100%) of peeler core sections in the core layer. This corresponds to effective percentages of panel surface glued with peeler core slides of 80%, 64%, and 48%, respectively. The physical properties (density, water absorption, and thickness swelling) and mechanical properties (bending strength (MOR) and modulus of elasticity (MOE)) of the laboratory-fabricated hybrid panels were determined in accordance with the applicable European standards (EN 310, EN 317, and EN 323). The highest MOE and MOR values of 3575 N·mm−2 and 28.1 N·mm−2, respectively, were obtained for the hybrid poplar plywood panels with a thickness of 20 mm and 100% peeler core sections. The use of beech veneer in the face layers did not lead to a significant increase in the mechanical properties. In this case, the MOE and MOR values of the hybrid plywood panels with a thickness of 20 mm and 80% peeler core sections were 5954 N·mm−2 and 35.2 N·mm−2, respectively.