Macmillan Bloedel Limited

George N Rosenberg

Derek Barnes

Jan A Dessens

A high wet strength waferboard panel is disclosed made from aspen species of wood flakes or equivalent with average specific gravity less than 0.6 and having wet strength equivalent to plywood. At least a portion of the wood wafers are oriented generally in a lengthwise direction such that the length to width strength ratio of the panel, measured as modulus of rupture, is in the range of about 1.3:1 to 2:1, the density of the waferboard panel being in the range of about 38 to 45 lb/ft.sup.3, the content of adhesive resin in the panel being in the range of about 4% to 10%, the content of wax in the panel being in the range of about 1% to 21/2% and the thickness of the panel being in the range of about 3/8 to 11/2 inches. The fully soaked panel having a moisture content of at least about 30% with an MOR lengthwise greater than about 2900 lb/in.sup.2 and an MOE lengthwise greater than about 0.9.times.10.sup.6 lb/in.sup.2.

High wet strength waferboard

An apparatus is disclosed for blending wood strands with a liquid resin. A process is also disclosed for continuously blending wood strands with a liquid resin. The apparatus overcomes some of the problems that exist with present day blenders because it avoids clogging spray nozzles and allows complete coating of the strands with a minimum amount of resin. The apparatus forms a substantially constant flow of wood strands into a first falling curtain of separated wood strands, the first curtain having a predetermined substantially constant width, a first liquid spray including at least one spray nozzle located on each side of the first falling curtain of separated wood strands away from the first falling curtain, adapted to spray liquid resin droplets for the width of the first curtain, but not substantially beyond; collector for collecting the first sprayed wood strands and forming them into a second falling curtain of separated wood strands, the second curtain having a predetermined width, and a second liquid spray including at least one spray nozzle located on each side of the second falling curtain of separated wood strands away from the second falling curtain, adapted to spray liquid resin droplets for the width of the second curtain but not substantially beyond.

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Vancouver, Canada

George N Rosenberg