Effects of silvicultural practice and veneer layup on some mechanical properties of loblolly pine plywood

Loblolly pine (Pinus taeda) three-ply plywood was manufactured from veneer obtained from silviculturally different stands. Panels from each site were assembled with four different veneer grade arrangements and tested in wet and dry conditions. Stiffness properties in both the wet and dry conditions and strength properties in the dry condition were all significantly affected by silvicultural practice ; veneer grade arrangement also showed significant differences. Shear strength and bending properties (MOR and MOE) were most favorable with panels manufactured from all A-grade veneer (AAA). Strength properties were found to be very similar between panels manufactured with A-grade veneer on one face and C-grade veneer on the other face and in the core (ACC), and A-grade veneer on both faces and C grade veneer in the core (ACA).