Further to the successful mill trial at Federated Co-operatives Limited in August 1995, a need to optimize the veneer lathe incisor and determine the benefits was identified. While the feasibility study was carried out directly at the mill, a majority of this work was conducted at the Forintek laboratory. During the early stages of this project, much effort was given to upgrade the Forintek 14-inch mini-lathe so that it could run with an incisor bar. Then an incisor bar assembly was fabricated for bar pattern tests. Finally, a series of tests were conducted to determine the optimum operation condition for an incisor bar and the effects of incising on veneer quality and recovery. The results showed that veneer is much flatter when peeled with a combination of incising and overdriving during peel. Species has a very strong effect on veneer flatness, especially spruce. Bar overdrive seems to be as equally important as incising. For the mini-lathe with which the tests were carried out, a 100.5% overdrive seems to yield the flattest veneer. Peeling speed and log conditioning has much less effect on veneer flatness than species and overdrive. Faster peeling speed and lower conditioning temperature seem to favour veneer flatness. According to the laboratory tests, veneer recovery can be increased by 5% from veneer stretching and flattening and reduction of spinout. An initial comparison also reveals that veneer peeled using an incisor bar may have less thickness variation and surface roughness. As a recommendation, further tests should be carried out to determine the effects of incising on other processing and performance properties such as pressing and bonding. The incising technology should be implemented in plywood mills, particularly in the softwood plywood mills, which use a big bar lathe, because an incisor bar can be easily retrofitted.
Full-scale test results of the MIDPLY™ wall system are presented along with the test results obtained on nailed joints with single and double shear planes. Research findings to date indicate that MIDPLY™ shear wall is a cost effective wall system, which has superior lateral load resistant capacity when compared to standard wood-frame shear walls. The effects of nail type and spacing, number of shear planes, panel type and thickness, vertical loads, exterior sheathing, and end stud configuration on the lateral load carrying characteristics of MIDPLY™ wall system are studied. Comparisons with the standard shear wall system are made. Based on the findings in the first year, a standard MIDPLY™ shear wall system is selected and will be used as the basis in the second year of this project. An industrial advisory group including two prefabricated home manufacturers, and a major wood products producer was established. A meeting of this group took place where key issues were discussed.
The recent emphasis on producing higher value secondary wood products in British Columbia requires some changes in the way manufacturers process wood. A basic requirement in assessing whether a wood species is suitable for use as a value-added product is an understanding of the wood's machining characteristics. The objective of this study was to determine the planing, turning, shaping, boring, mortising, sanding, and fastening characteristics in clear wood sections for 15 B.C. softwood and hardwood species:
1. Amabilis Fir, 2. Douglas fir, 3. Lodgepole pine, 4. Sitka spruce, 5. Subalpine fir, 6. Western hemlock, 7. Western larch, 8. Western redcedar, 9. Western white pine, 10. Western white spruce, 11. Yellow cedar, 12. Black cottonwood, 13. Red alder, 14. Trembling aspen, 15. Western white birch.
This information will aid B.C. secondary wood processors in the design and manufacture of higher value products, and help promote B.C. species and products in domestic and export markets. The study compares the machining properties of individual species within B.C.'s SPF and hem-fir groups demonstrating the benefits of sorting by individual species. In addition, the machining properties of B.C.'s under-utilized species (e.g., trembling aspen, black cottonwood) are compared to those of well established softwood species (e.g., Douglas-fir, western hemlock). Finally, the study determined the average force necessary to withdraw two types of fasteners (nail and screw) from each of the wood species. A tabular presentation of the results is included for easy comparison between species.
Mechanical properties - Machining
British Columbia woods - Utilization
Abies amabilis - Mechanical properties
Pseudotsuga menziesii - Mechanical properties
Pinus contorta Dougl. var. latifolia - Mechanical properties
The purpose of this increment borer owner's manual is to provide the reader with a number of increment core collection "tricks-of- the-trade" which will help in collecting consistently high quality cores. It is aimed at a wide audience, from novice to experienced workers. In general improved core quality translated into considerable savings of time and expense. At the same time the accuracy and precision of ring width and density determinations increases.
In 1997, Forintek initiated a project entitled "Improving Resin Distribution in OSB" with one of its objectives to determine the feasibility of a relatively inexpensive (<$10,000 Cdn.) and user friendly image analysis system developed by Forintek and designed to measure phenol formaldehyde (PF) resin distribution. An evaluation of the system, now described as the Resin Distribution Analyzer (RDA), is described in this report.
Forintek and its members have recognized the need to introduce more market pull information for both the conceptualization and implementation of individual research and development projects. This project develops a methodology to critically analyze opportunities for competitive advantage for Canadian wood products in our markets. The objectives of this project were to develop a methodology for identifying what wood product attributes are being demanded in Japan by end-use and to record wood product flow information with as much product detail as possible; identify trends over the past five years, identifying products with which Canadian products have or are beginning to compete (including Japanese domestic production); and to develop a methodology to incorporate product detail into a trade-flow model. Japan was used as an illustration of the methodology, but it is designed to be generic enough to apply to any market segment.
Face veneers for high-grade plywood have solid wood surfaces free from knots and defects. These plywood panels are used where a high quality finish is required or where the surface appearance is very important. For less strenuous requirements the use of a patching compound to cover and seal open defects has become accepted in the international market place. Certification agencies evaluate plywood panel quality and durability and offer consumer assurance that the panel will perform satisfactorily over an extended period. With evolution of the plywood industry and their suppliers, new patching materials and methods have come into use. The long-term performance of plywood patches made with these new materials and methods may affect the long-term durability of the plywood panel. Currently available literature was reviewed to determine if current plywood industry patch test methods are adequate to meet consumer needs.
Research was carried-out to investigate the feasibility of electrostatically applying PF powder resin to OSB furnish to improve resin distribution and thereby improve panel properties. Research elsewhere has shown that resin distribution is an important factor affecting panel properties including internal bond strength and thickness swell. It was theorized that electrostatic charging would distribute resin more uniformly on strands compared to conventional application techniques and would help to strengthen the bond between resin and strands thereby minimizing resin losses and allowing for greater levels of resin to be retained on OSB furnish. Small-scale tests were conducted in Forintek's Vancouver laboratory followed by pilot plant tests at the Alberta Research Council (ARC) which involved electrostatically charging resin and aspen furnish in a pilot plant blender. Lab results showed that the average amount of resin retained by strands (retention) increased with electrostatic application compared to control applications. During pilot plant tests, image analysis results showed that resin coverage increased using electrostatics. Also, the coefficient of variation in resin coverage was lower for electrostatic applications compared to the controls. However, contrary to previous research findings, test panels made from electrostatic and control batches in a pilot plant did not show any significant differences in internal bond and thickness swell properties. Electrostatic application of powdered PF resin does not appear to sufficiently improve resin distribution in aspen to affect panel properties. Although pilot plant results were not promising, lab tests have shown that electrostatic application techniques are sensitive to material properties and that other wood species may be more suitable for charging than aspen. Further research will be continued at Forintek's eastern lab in the 1998/99 year to investigate electrostatic application of resins to mixed hardwood species.
The effects of different pressing variables were evaluated for the manufacture of hog fuel board made from western hemlock. In general, the hog fuel boards made at higher temperature and pressure exhibited better dimensional stability and durability properties. Pressing time was reduced with temperature ranging from 20 min at 260 C to 4 min at 315 C. It was demonstrated that good quality hog fuel boards could be produced using a high wood content of 65%. In all cases, the western hemlock hog fuel boards showed an average thickness swelling less than 10% after a 2-hour boil test. After the same treatment, OSB shows 50% thickness swelling and particleboard disintegrates. Preliminary results for bark / hog fuel boards made from three eastern species, white spruce, balsam fir and jack pine showed the boards exhibited excellent dimensional stability and durability properties. In the interests of furthering the preliminary market and economic feasibility investigations of bark board and in co-operation with Dr. A. Kozak and his 4th year marketing class (Dept. of Wood Science, UBC), exploratory analyses were done on four potential end uses. These were flooring, floor underlayment, roof shingles and furniture / cabinets.
Experiments were conducted to evaluate pressing of plywood and LVL using self-generated steam. For the 13-ply SPF LVL experiments, the average moisture content (avg. m.c.) in the outermost incised veneers was varied from 10 to 14% and for the 15-ply aspen LVL experiments the avg. m.c. was varied from 8 to 12%. For the 7-ply SPF plywood experiments, the avg. m.c. in the outermost incised veneers was 10 and 15%. In these experiments the controls and core incised veneers were 2% avg. m.c. Using the highest avg. m.c. in the outermost incised veneers, the pressing time for 13-ply SPF LVL was reduced by 31.1% and for 15-ply aspen LVL, 30.8 % and for 7-ply SPF plywood, 38.7%, compared to conventional hot platen pressing. The results showed that small changes in the avg. m.c. of the outermost veneers had a large effect on pressing time. Therefore, careful control of veneer m.c. under mill conditions would be very important. All the panels prepared under a variety of self-generated steam conditions exhibited excellent bond quality and the average % wood failure was much greater than 80% in all cases, thereby meeting the average % wood failure requirement in the CSA 0151 plywood standard. An economic analysis of return on investment for thick plywood products and LVL using self-generated steam pressing showed that a manufacturing plant would make a profit of about $3,000,000 per year.
Two methods of adding borate compounds to plywood panels were investigated. One method was patterned after successful efforts to incorporate zinc borate into OSB panels, where the borate is added to the adhesive. Zinc borate, which has shown some success in OSB, was however not sufficiently soluble and was replaced with a sodium borate. Method two involved the more traditional approach in pressure-treating wood veneers with a borate solution. A commercial borate compound (Timbor®) was used. The treatment target in each case was 2 % boric acid equivalent (BAE), which is the normal level being applied to solid wood. Borate addition to the adhesive was not successful for plywood due to the high level of borate required relative to the adhesive quantity. Treating of wood veneers prior to bonding yielded better panel bond quality results but showed large variation in borate retention levels within and between veneers. Treatment at the 2 % BAE target level did not produce panels with adequate bond quality. Treatment to 1 % BAE showed more promise but there were insufficient panels at the lower BAE level to allow for any evaluation of termite resistance.
The work presented in this report addresses the FRBC value-added research priority area and shows good potential for creating jobs in the forest products sector and leading to new technology for manufacturing a value-added product. Experiments were conducted to evaluate steam-injection pressing of 7-ply SPF plywood and 13-ply SPF laminated veneer lumber (LVL) on a laboratory scale at Forintek and a pilot plant scale at Alberta Research Council (ARC). The laboratory experiments provided a basis for the pressing schedules used in the pilot plant trials at ARC. The following parameters were necessary for the steam-injection pilot plant trials: Top and bottom screens (0.6 mm stainless steel 30-mesh screen), incised veneer and a phenolic glue (Borden 2020) resistant to washout. Using steam-injection technology in pilot plant trials, substantial reductions in pressing time were achieved both for 7-ply SPF plywood and 13-ply SPF LVL. Specifically, a steam-injection time of one minute using saturated steam at 80 psi reduced the pressing time of 7-ply SPF plywood by 27% compared to conventional platen pressing. A steam-injection time of eight minutes using saturated steam at 80 psi reduced the pressing time of 13-ply SPF LVL by 32% compared to conventional platen pressing. Both the control and steam-injected 7-ply SPF plywood and 13-ply SPF LVL panels exhibited excellent bond quality and the average percentage wood failure was much greater than 80% in all cases thereby meeting the average percentage wood failure requirement in the CSA 0151 plywood standard. There was no significant difference in shear strength between control and steam-injected shear specimens. There was no statistical difference in average modulus of elasticity or modulus of rupture under flatwise and edgewise bending for the steam-injected LVL compared to the control LVL made using conventional platen pressing. A previous economic analysis of return on investment for thick plywood products and LVL showed that a 30% reduction in pressing time for a medium-size manufacturing plant would generate an additional profit of $3,000,000 per year.
Although the code provisions for addressing the long-term structural performance of wood products are based solely on tests on solid sawn lumber or on defect-free wood, these provisions are currently applied to composite or engineered wood products. There are concerns among code writers that some composite wood products may not necessarily exhibit the same long-term behaviour as lumber or defect-free wood. In order to address these concerns, a standard test needs to be developed for assessing the long-term performance of such products. Although test protocols are available from previous studies, the extensive testing originally conducted for lumber was judged impractical for composite wood products. This is because of the proprietary nature of composite wood products and the desire to allow manufacturers, whenever possible, the ability to alter a product to suit the available fibre resource and market demands. These conditions are particularly valid during initial product development where rapid and cost effective assessment procedures are needed. An American Society for Testing and Material (ASTM) subcommittee was therefore established to prepare an appropriate consensus standard. This project is designed to allow Forintek staff to participate in that process as well as develop the baseline performance data for lumber, which the composite product performance will be compared to, in the proposed ASTM standard. The members of the two Task Groups of the ASTM Section D07.01.04 prepared a draft of the "Standard Specification for Evaluation of Load Duration and Creep Effects for Wood Products". This draft included a simple verification method, and more extensive probabilistic-based method. The verification method requires the producer to demonstrate that his product has equal or better long-term performance than lumber, while the probabilistic-based approach requires producers to develop extensive test data and then perform analysis to quantify the DOL and creep factors. The verification test portion of the draft standard has been applied to a sample of lumber to obtain the baseline performance data at low load levels. Results showed that this group fulfilled the requirements stipulated in the verification method in the draft ASTM standard. The ASTM draft standard has been balloted at the section level. As a result of comments received, the probabilistic-based approach was dropped. Consequently the current draft, which is planned to be balloted in April 1998, references only the verification method. Representatives of the structural composite lumber industry have also proposed to incorporate the verification portion of the draft standard into the ASTM Standard for Structural Composite Lumber. They prepared a paper including this approach, and compared the DOL performance of some composite lumber products against the lumber results provided to them by Forintek and the USFPL. They found that the verification method can be used to check the equivalency of the long-term structural performance of two composite lumber products. The Canadian Standards Association Technical Committee on Engineering Design in Wood has accepted the methodology given in this paper. The ASTM Section on Structural Composite Lumber will review the work on Test Methods and Evaluation of Load Duration and Creep Effects to ensure that the effort is not being duplicated.
Optimization programs, full-profile scanning, and powerful computers used with auto-rotation systems make thorough log rotation, log positioning and sawing decisions possible. However, high log throughput, bumpy log surfaces, and heavy sawlogs make accurate mechanical execution difficult. How accurately can auto-rotation systems execute thorough log rotation and log positioning decisions? Two mill tests were carried out to estimate rotation errors and unintentional log movement. OPTITEK®, Forintek's log breakdown simulator, was used to analyse the effect positioning errors have on the economic benefits of auto-rotation systems.
This study examines the utility of using hybrid poplar in typical woodworking processes. Three processes were considered: machining (including fastener withdrawal), laminating and finishing. In addition the effects of kiln drying on shrinkage and warp and general strength properties of hybrid poplar were also evaluated.
Wood failure evaluation is the key criterion for predicting the long-term durability of plywood. At present, the conventional visual method for plywood wood failure evaluation is slow and subjective. Evaluations can be influenced by factors such as: room lighting, wood species, sample treatment, and readings from prior samples. An automated wood failure evaluation system using image analysis techniques could potentially be programmed to consider all the variables and respond with consistent wood failure values regardless of the machine operator's experience level. This report describes the results of a six-month study in which a system for automated plywood wood failure determination was compared with conventional visual wood failure evaluation. It was built upon research undertaken in the 1996/97 year in which the feasibility of the approach was initially established. In the research reported previously, a colour optical imaging system was assembled and suitable wood failure algorithms were compiled with promising results. The imaging system was 100 % effective in reproducing sample values. The data were discussed with the project liaisons and a three-month comparison with Canply readings was suggested. In this study, machine evaluation of 4,150 samples was compared with readings of monthly plywood mill quality control samples. The sampling was designed to include all British Columbia plywood mills and all categories of commercial plywood production. The differences in average values for wood failure between human and machine evaluation were found to be less than plus or minus 5% in the majority of cases. In addition, 93 % of ‘set average' readings fell in the plus or minus 10% range of deviation expected of human wood failure readers. Agreement on readings of individual samples within each set was not quite as good with 72% falling in the plus or minus 15% range.
