A series of dispersion-resin plywood formulations were prepared in the laboratory and their bond performance assessed on incised spruce veneer at 10% m.c. Excellent bond quality results were achieved in these laboratory experiments as indicated by high average % wood failure values of over 90%. To further develop the plywood dispersion resin, a pilot plant trial at a gluing company was conducted and again excellent bond quality results were achieved. A large quantity of the plywood dispersion resin was prepared and a successful mill trial at Cantree Plywood was carried out. This trial demonstrated that more dimensionally stable panels can be prepared from high m.c. veneer. The waferboard dispersion technology developed in this study helped facilitate a mill trial using high moisture content face wafers.
The purpose of this small study was to examine the effect of various test methods upon the bending moduli of elasticity and to determine the bending strength of selected Douglas-fir and spruce laminated veneer lumber specimens.
This study evaluated the effect of two different incisors followed by chromated copper arsenate pressure treatment on the bending strength and stiffness of No. 2 and better nominal 2 x 4 inch (38 x 89 mm) spruce-pine-fir and hem-fir lumber. The double-density incising method, developed at Forintek, allows SPF to meet the CSA O80 wood preservation standards. The high-speed incisor was developed by Forintek for operation immediately behind the planer in a sawmill to produce a treatable lumber product. The prototype tested here employed two solid rollers to lay down two superimposed patterns of incisions at a density of 17500/m2. Approximately 2900 specimens of SPF and 1200 specimens of hem-fir were sorted into nine and four matched groups, respectively, according to their average flatwise modulus of elasticity values tested in centre point bending. The matched groups were then given various combinations of drying, incising and pressure treatments. Bending strength properties were tested. It was found that kiln-dried SPF and green hem-fir commercial dimension lumber, treated by the above processes, can be safely used for all structural purposes for which preservative treatment is required.