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Essay:
OSB - FPL/USDA descriptionOriented Strandboard (OSB) is a structural panel that competes directly with softwood plywood in many construction applications. particularly exterior wall and roof sheathing and nearly half of all floor decking. OSB was first produced in Canada in 1964. Since then, capacity has increased steadily, but it wasn't until the mid 1980s that capacity expanded rapidly. North American production capacity in 1996 was estimated at 15,276 กม 103 m3, nearly twice the 1990 capacity (2). The number of operating mills producing OSB increased by more than 50 percent between 1990 and 1996. This increase in the rate of industry expansion is a direct result of harvest restrictions on West Coast timber. OSB is made from small diameter softwoods and previously underuti-lized hardwoods and is therefore not dependent on the large diameter logs needed by the softwood plywood industry. West Coast inland mills producing OSB primarily use lodgepole pine logs averaging about 0.25 to 0.3 m (10 to 12 in.) in diameter. compared with the 0.4- to 0.5-m (16 to 20-in.) logs needed for softwood plywood (Table 1). Mills in the South producing OSB use pine plantation thinnings and Southern Pine and soft hardwood logs that average about 0.2 m (8 in.) in diameter. Log diameter in the South has gotten smaller. Northern mills rely almost exclusively on aspen logs 0.15 to 0.3 m (6 to 12 in.) in diameter. The diameter of these logs has remained fairly constant.
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