An Evolutionary History of Oriented Strandboard

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New house construction with OSB underlayment.

A new FPL report, by retired Wood Technologist John I. Zerbe, Supervisory Research Materials Engineer Zhiyong Cai, and retired Economist George B. Harpole gives us the story behind a product that we all use and take for granted every day.

An Evolutionary History of Oriented Strandboard (OSB) tells us that historically, logging and wood processing residues offered a utilization challenge for those who harvested and manufactured wood products. Logging operations typically left stumps, tapered log butts, tree tops, and limbs for forest fires to remove or to compost into bed­ding for destructive forest insects.

Even after the delivery of logs to a sawmill or plywood plant, residue materials have represented up to 60% of the log volumes delivered. Thus, commercial efforts have attempted to utilize as much of these residue volumes as possible with production of char­coal, poultry bedding, and heating fuels. Forest fires, tepee burners, and burn piles, however, have often provided a quick answer for getting rid of the surplus accumulations of forest and processing residues. Today, with the increased use of logging residues and wood chips for production of OSB panels, about 80% of the wood volume removed from the forest is now processed into marketable products and tepee burners no longer exist for getting rid of processing residues.

The pathway to OSB production appears to have started in the 1920s with production of hardboards from pulp mats that were produced from wood chips. This was the begin­ning for producing composite panel products from wood residue types of materials. Following hardboard production and skipping the pulping step for producing hardboards, the utilization of waste materials was increased in the United States in the 1940s by the production of nonstructural and appearance grades of particleboards. Even as a nonstructural product, the particleboard made in the United States was new compared with plywood.

Manufacturing OSB.

Manufacturing OSB.

But with the decline in the availability of timber suitable for plywood production in the 1970s, the development of technologies for production of structural types of particleboards quickly became a top priority for wood products research. As technology advance­d various products were produced along the way until researchers developed the oriented strandboard or OSB panels we speak of today.

Ideas for particleboard originated in Germany in the 1930s, and the prod­uct yield from harvested trees was only about 40%. Today, with increased use of wood chips and sawdust, logging residues have been reduced to less than 10%, with little to no processing residues to dispose of. OSB is ubiquitous because OSB panels have been essentially a problem-free new commodity wood product. Perhaps no other new wood product has ever been so problem free as OSB com­posite panels.