Weathering performance of particleboards manufactured from blends of forest residues with red pine (Pinus brutia) wood

Abstract

Red pine cone and barks combined with red pine wood particles in various proportions were used as the raw materials for one and three layered experimental particleboard manufacturing in laboratory conditions. The pine cones and barks have higher lignin, but lower holocellulose content compare to wood. For bark-based panels, the highest MOR (2.52 MPa) corresponded to the lowest thickness swelling (9.3%) and marginally highest IB at 150oC and 8% adhesive level. The 24 hour thickness swelling (TS) values obtained in this study were lower than the required TS-EN 312 (2005) value of 14% for all bark-based boards. However, the single-layer bark-based boards demonstrated higher mechanical properties compared to three-layer boards using similar manufacturing conditions. The boards exposed to atmospheric conditions have considerably darkened (-DL) and lower surface roughness changes. Meanwhile, for single-layer cone boards, the highest MOR (4.66 MPa) was found at 150oC and 8% adhesive level, whereas the highest IB (1.54 MPa) and lowest TS (32.9%) were found at 150oC and 10% adhesive content. The cone-based panels had higher surface color changes (lightness and total color difference) compared to red pine wood panels. The particleboards produced using cone in the proportion of wood resulted in lower TS compared to boards made from only red pine wood.