Dimensional stability and mechanical properties of oriented strandboard with microwave-dried flakes in the surface layers

The behavior of oriented strandboards manufactured with flakes dried to various moisture contents using microwave energy was examined. Boards manufactured with surface layers of microwave-dried flakes had slightly greater mean thickness swell than boards with untreated flakes, but this difference was proven to be statistically insignificant. Density profiles of boards with microwaved flakes in the surface layers matched the profiles of the boards with untreated flakes. Internal bond strength, as well as tension, compression and bending strength, and modulus of elasticity were not significantly affected when boards were manufactured using microwave-dried flakes. The moisture content to which the flakes were dried with the microwave did not affect board behavior or performance. This response is notably different compared to solid wood, where it has been shown that microwave drying of relatively thick specimens has considerable adverse effects on tensile strength.