Machined tapers reduce the differential edge swelling of oriented strand board exposed to water

The objective of this research was to optimize the dimensions of machined tapers (bevels) at the edges of oriented strand board (OSB) to reduce the differential edge swelling (edge-flare) that causes problems when OSB is exposed to water. Machining an edge-taper, 0.6 mm-deep and 10 or 20 mm-wide eliminated edge-flare, but shallower tapers, 0.2 or 0.4 mm deep, were less effective. The combination of a 0.6 mm edge-taper and an effective edge-seal allows manufacturers of OSB to produce composite panels with reduced tendency to develop edge-flare, without having to modify the physical characteristics of panels or add additional adhesive or wax to the composite.