The B.C. Wood Specialties Group (BCWSG) laminating mission to Japan took place May 14-22, 1994 and involved visits to Japanese companies and industry associations in Nagoya, Osaka, and Nara. The mission was led by Mr. Peter Fisher, Director, Resource Industries Branch, B.C. Ministry of Employment and Investment. The purpose of the mission was to make contacts and to gather information so that the B.C. wood remanufacturing industry could capture further market opportunities during the trip and identify possible future markets for B.C. wood products.
The highlights of a co-operative research program developed by the U.S. Forest Products Laboratory (FPL) and Forintek Canada Corp. to provide detailed creep-rupture and some creep information for composite panel products are summarized here. Support for this program has been provided by the American Plywood Association, The Waferboard Association (now the Structural Board Association), as well as the U.S. and Canadian Forest Services. Commercially produced plywood, oriented strandboard (OSB), and waferboard were tested to identify three mills that produced panels with high, low and median flexural creep performance. These three plywood, three OSB, and three waferboard products were then extensively tested to provide information on their duration of load and creep performance.
The bending properties of aspen waferboard can be improved by increasing the resin content and/or board density. These options, however have limited effect and are very costly. On the other hand, panels produced with longer, oriented stands have demonstrated significant improvements in bending strength and stiffness. The panel industry has recently used wafers or strands up to approximately 102mm (4in), however, the utilization of much longer material is practical. In addition to more efficient use of the wood resource, structural panels with improved properties can penetrate more demanding applications, particularly as future engineering materials, and overcome some problems experienced with traditional wood composites such as creep. The overall objective of the study was to demonstrate that by using long strands, coupled with appropriate strand alignment, strand thickness, and face-to-core layer ratio, a structural panel can be produced with superior strength and stiffness in the aligned direction while maintaining adequate properties in the cross direction. The specific objective for this year's work was to establish the improved performance using panels produced in structural sizes and under conditions that parallel those of the industry more closely. Manufacturers of oriented strandboard and waferboard can use the information to produce high performance OSB panel products with minimal effects on production parameters and costs.
In recent years, a number of well publicized fire incidents have raised serious questions about the levels of fire safety afforded Canadians by current NBCC specifications for fire performance of exterior cladding materials and spatial separation between buildings.
Six impregnating phenol formaldehyde (PF) resins having low to moderate molecular weight were synthesized and evaluated for their wood veneer penetration and curing properties. Based on the results from the penetration and curing properties studies, a PF resin designated as B-2 was used to impregnate subalpine fir, white spruce and lodgepole pine veneer. LVL panels, 12 x 12 inch, were prepared with these veneers. Both modulus of rupture (MOR) and modulus of elasticity (MOE) were increased by 10 to 15% for the resin-impregnated LVL made from each of the SPF species. Edgewise bending results for specimens cut from 2 x 4 foot white spruce LVL panels showed an increase of 15% both for MOR and MOE for the resin impregnated specimens. As well, the dimensional properties (% edge swelling and % water uptake) of the SPF LVL panels were improved by 50% using the patented Forintek resin impregnation method.
A series of plywood and laminated veneer lumber (LVL) panels were prepared using veneers with higher than normal moisture contents in face and back layers. The purpose of the work was to evaluate the effects of self-generated steam on the pressing times and panel warpage. Panels made with 6% and 10% m.c. faces and backs were compared with control panels made with all dry veneer. Thirteen- ply 40 mm (1 5/8 inch) thick panels were evaluated for press times and thin 9.5 mm (3/8 inch) panels were evaluated for cupping and bowing. Normal plywood press temperatures and adhesives were used. All panels were made with incised 3.2 mm (1/8 inch) SPF veneers. The project demonstrated that substantially shorter press times and more dimensionally stable panels can potentially be made using higher moisture content outside veneers.
Wood quality is defined as the suitability of wood for a particular end-use. Wood anatomy and tree growth are discussed in terms of macroscopic and microscopic features of a tree examined in cross section. End-use requirements are described in terms of lumber grading. The following wood quality attributes are introduced, defined and discussed in terms of their practical implications for wood processing and wood products: wood density, density variation, juvenile wood/mature wood distribution, proportion of heartwood/sapwood, fibre length, fibril angle, compression wood, knots, grain and extractives. The potential for influencing tree growth characteristics (eg. wood density, branch size) and wood quality (structural and appearance lumber grades) through stand stocking control is discussed. Foresters are asked to consider the wood quality implications of site specific silvicultural operations.
The use of microorganisms for the protection of lumber from mould, stain and decay is an alternative to the use of biocides that could allow the sawmill industry to decrease the use of chemicals. Successful implementation of bioprotection requires a basic understanding of the effects of biotic and abiotic factors on the physiology, biology and ecology of sapstain fungi and bioprotectants in situ. Knowledge of the ranges of abiotic factors under which a bioprotectant will survive, germinate, grow and be competitive is essential to achieve consistent and efficacious protection. Identification of such factors would enable its inclusion in the deployment milieu. In addition, development of methods to monitor the bioprotectant on lumber would also aid in the study of population dynamics and is essential for quality control and assurance.