Ce rapport decrit l'etat d'avancement des travaux sur le developpement d'un modele de simulation et d'optimisation du procede de transformation des bois en sciage. L'approche adoptee pour la construction de ce modele y est decrit en detail. Des annexes sous forme d'articles scientifiques, d'actes de conferences et de rapports de travaux d'etudiants gradues sont aussi incorpores au present rapport afin de faciliter la comprehension du lecteur.
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.
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.
Forintek has for many years assisted the industry by applying its extensive knowledge base in drying to address many of the common problems associated with, for example, schedule development, degrade prevention and quality control. Jointly the East, West and Laval scientists are formally developing the information and infrastructure to establish the corporation as a recognized world leader in knowledge and technology for the drying of Canadian softwood lumber.
The purpose of this study was to determine if press-drying of redry veneer is a practical option for the plywood industry. Two press-drying schedules were tested - one minute and two minutes at 340 degrees F with 10 psi press pressure. Drying two redry sheets per opening for two minutes gave the best results. Moisture pockets in the veneer were reduced to an acceptable level and moisture equalization occurred between the two sheets in the press and during the veneer load cool-down time. Press drying redry veneer may provide a relative low cost processing option for mills to complement more capital-intensive alternatives such as radio-frequency (RF) drying.
Steam press drying of green SPF veneers was evaluated on a 4 x 8 foot prototype steam press set up at a local plywood mill. A used industrial press has been modified into a single opening oil heated hot press with grooves machined into the upper platen. Standard green nominal 4 x 8 foot 3.2 mm (1/8 inch) thick mill veneer was dried with super-heated steam injected through 6 mm (1/4 inch) holes in the bottom platen. All veneers were incised with Forintek's patented veneer incisor. The project demonstrated that steam injection can dry green veneers three to four times faster than conventional veneer driers. From the results of this project, a study on the press drying of redry veneer was initiated and showed good potential for industrial implementation.
A shipping trial was done to determine the fungicidal efficacy of the sapstain control products PP523 or F2 applied using the Electrodyn or an hydraulic/electrostatic (H/E) spray system, in comparison to the performance of a conventional hydraulic spray treatment of NP-1. Test packages of treated lumber, as well as untreated controls, were stored at Vancouver, B.C., and at Tampa, Florida. The packages were opened and rated for growth of fungi at 4.5 and 11 months.
This paper investigates the feasibility of increasing bandmill production by proportionally increasing both blade speed and lumber feed speed. A modal analysis of the bandmill and bandsaw was conducted and resonant conditions, likely to impair performance, were identified. Cutting tests were conducted to determine the effect of increased blade speed on cutting accuracy, surface finish and sawdust quality. The tests were conducted at blade speeds of 10,000 fpm, 12,500 fpm and 15,000 fpm and examined the effect of tipped and swaged blades cutting Coastal Hem/Fir and Interior SPF.
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.
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.
Water soluble borates such as (Tim-Bor[tm]) are recognized for their efficacy in protecting wood and wood products form fire, insects and decay. Unfortunately they have been found to have an adverse effect on the mechanical properties of composite panels. In this study, attempts have been made to improve the adhesive bonds of the borate-treated panels and to confirm the practicality of producing borate-treated panels in a mill operation.