Alternative plywood manufacturing from poplar veneer

This study aims to produce alternative plywood using I-77/51 poplar rotary-cut veneers and investigate their effects on the physical and mechanical properties of the produced material. In this study, 7, 9, and 11-ply boards were produced using FF glue. Press pressure was maintained at 8 kg/cm² and the press temperature was maintained at 125°C, with a pressing time of approximately 1 mm/min. While preparing the board draft, for 7-ply boards; 7-ply plywood, 7-ply alternative plywood and 7-ply KTK 3 different boards; for 9-ply boards; 9-ply plywood, 9-ply alternative plywood-I, 9-ply alternative plywood-II and 9-ply KTK 4 different boards; for 11-ply boards; 11-ply plywood, 11-ply alternative plywood and 11-ply KTK 3 different boards, thus veneer orientation combination studies were carried out on 10 different boards. The physical properties of the produced boards were determined according to the density TS EN 323 (1999), the determination of the amount of water intake TS EN 317 (1999), the determination of the thickness increments TS EN 317 (1999); the mechanical properties were determined according to the bending strength tests TS EN 310 (2010), the elasticity modulus TS EN 310 (2010) and the adhesion resistance TS EN 314-1 (1998) standards. Among the board groups, the highest density was 0.51 kg/cm3 for 9-ply alternative plywood-I. The density of the boards increased with increasing pressing time. Water uptake was at least 7 KTK in 2 hours, and 24-48-72-96-120 hours for 9-ply alternative plywood-I. The water uptake results of the test samples indicate that they can be used interchangeably. Thickness swelling was at least 11 KTK in 2 hours, and 7 KTK in 24-48-72-96-120 hours. This is consistent with the water uptake values. The mechanical properties of the boards showed that bending strength and modulus of elasticity increased with increasing the number of parallel orientations of the veneers, with the highest values found in 7, 9, and 11-ply KTK. The highest bonding strength value in these combinations was determined in 9-ply KTK. The test results indicated that alternative plywood exhibited higher mechanical properties than plywood and values closer to KTK. Because it is produced with FF glue, it is recommended for humid and outdoor use.