Manufacturing analysis using computer flow simulation has been applied successfully in pilot projects to several Alberta value-added wood products companies in the sectors of re-manufacturing and furniture manufacturing. This project continues these pilot projects examining the application and potential benefit in manufactured/prefab homes. An Alberta manufactured/prefab home manufacturer was selected for this project. The wall-line was chosen for this study. The study was accomplished through detailed observations and data collection, which identified several bottlenecks that included the framing table, squaring table and the linear configuration of the line. From observations, the squaring table was labour intensive and the material handling equipment was quite slow. At the framing table, the stud grade being used contained many twisted and bowed boards, which required additional time to align and fasten the studs. Lastly, the single-line configuration created bottlenecks during the transition from sheathed and unsheathed products. From observations and discussions with staff, potential improvement scenarios were developed. Simulation models were developed for each of these scenarios to evaluate their effectiveness and return on investment. The scenarios examined were: affect of panel sheathing ratio, improving efficiency at the squaring table, improving efficiency at the framing table, addition of a branch-line for unsheathed products and the addition of the branch-line in combination with increased efficiency at the framing table. The implementation of pre-cut OSB panels was simulated to reduce processing times at the squaring table by 30%, which increases throughput by 15%. The addition of a branch-line for unsheathed products showed a potential production increase of 10.8%. However, the simulation models also showed that the framing table could not maintain a consistent supply to the squaring table. The use of a higher stud grade was modelled showing a potential production improvement of 17.5%. As a result, the potential benefits in this particular wood products business demonstrates that computer flow simulations can be applied to Manufactured/Prefab Home manufacturers and may potentially have further implications in other similar Alberta value-added industries.
Radiation curable coatings are presently the standard in the wood flooring industry. Their great properties paired with their fast curing explain why they are now the most used coatings for prefinished wood flooring. Although important improvements can still be brought to these coatings. During the last years, nanoparticles have gained increasing interest in the paint and coatings industries. It could lead to similar results for the thermoset materials.
In this project, metal oxides (alumina, silica and zirconia) and clay nanoparticles were added in a typical UV acrylate formulation for wood flooring. This formulation was chosen mostly for its wear resistance, low yellowing and fast curing.
Nanoparticles were added in the acrylate formulation by different techniques (high speed mixing, ball milling, bead milling and three roll milling). Then, article size characterization was performed. Different techniques were employed according to the nanoparticles studied (metal oxides or clay). Microscopic experiments were also performed with an aim of supporting these results.
Then, nanoparticles and coupling agents addition effects on curing (speed and percentage of curing) were studied by photo-calorimetry (photo-DSC) and real-time infrared spectroscopy (RT-FTIR).
Mechanical properties (hardness, adhesion, scratch resistance, wear resistance, direct and reverse impact resistance) were evaluated. Optical properties (color, gloss, haze and optical clarity) and thermal properties were also assessed.
For clay-based coatings, an analysis of variance (ANOVA) was performed in order to determine if clay loading and clay dispersion affect the mechanical and optical properties.
In this study, current market share for wood in British Columbia non-residential construction was determined as well as potential for increased consumption of wood, based on a 194-building sample of 2006 building permits from most of BC’s major cities. For the sample, structural materials used in each project were established through phone interviews with each architect, contractor or other individual associated with the construction of the building. Each project was then compared against the height and area limits for combustible construction as defined in the BC Building Code. In actual market share for 2006, 13% of all buildings (which comprise 5% of all area) were primarily framed in wood. Adding in buildings that were partially framed in wood, 25% of all buildings (22% of all area) are using wood, either primarily or in combination with other structural materials. If every building allowed by code to be entirely framed in wood actually was, seven times more constructed area would be using wood than current practice. Adding in the potential for heavy timber roofs on non-combustible buildings yields a total of eleven times more constructed area that could be using wood. This total potential incremental wood consumption is estimated at up to 27 million board feet of lumber-type products (lumber, trusses, glulam, I-joists and composite lumber) and 13 million square feet of structural panels (plywood and OSB). Previously gathered market intelligence in BC and elsewhere in North America was then reviewed together with the market share statistics to help determine a set of near-term recommendations for the BC WoodWORKS! program to help capture some of this potential market.
Recent advances in scanning technology have enabled the detection of surface defects in green boards. This report is the second phase of a project that was initiated to investigate the benefits of surface defect scanning (grade scanning) on the value of lumber that can be recovered from optimized edgers. The first study focused on BC Interior mills and found that little or no potential increase was available. In this study, the benefits for mills processing large logs into high value products (e.g. BC Coastal sawmills) were investigated. Sixty-six hemlock cants were evaluated, with cant widths from 12 to 27 inches - large enough to allow multiple sawing solutions. After a sawing solution was generated for each cant by an optimized shifting-saw gang edger, using only profile scanned data, a grader, taking visible defects into account, proposed alternate sawing solutions. The values of all sawing solutions were calculated and for 76% of the cants, a sawing solution proposed by the grader was more valuable than the one generated by the optimizer.
The study found that an average increase of 29% in the value of large cants was available when edging decisions took surface defects into account, in comparison with the value resulting from optimization based on cant profile alone. However, it should be noted that the accurancy of vision systems will likely be less than that of a human grader so the actual gains will likely be somewhat lower.
Delamination currently accounts for approximately 85% of customer complaints about plywood as a sub-flooring product. It has become an urgent issue to many of our plywood members. It is estimated that by merely reducing 1% delamination in a 250 million ft2 (3/8 –in basis) plywood mill, the potential annual savings will be approximately $650,000. To help reduce plywood delamination, the key objective of this project was to develop a generic best practice checklist as a guide for manufacturing plywood.
A generic best practice checklist for manufacturing plywood was compiled with a focus on the following four key checkpoints: veneer peeling, veneer drying, panel gluing/lay-up and hot pressing. Key process variables at each checkpoint were determined as follows: peeling related veneer surface roughness and thickness variation, drying related veneer moisture content (MC) variation and surface inactivation, veneer temperature, glue coverage and dryout, and pressing time and pressure. Some technical issues were proposed to revisit as a strategy to reduce panel delamination. Among them include optimal lathe bar gap and pitch profiles, and proper knife sharpening for peeling, reduction of veneer overdry during drying, real-time adjustment of glue spread for adequate glue coverage, and use of optimum pressing time/pressure for adequate level of panel compression and glue curing. The resulting generic checklist can be modified for individual mill use.
Through literature review, pilot plant tests, and mill trials, the main causes of panel delamination were identified as: 1) glue dryout from long assembly time and high veneer temperature; 2) low panel compression, light glue spread or glue skips due to rough veneer; 3) little glue transfer due to veneer surface inactivation; 4) inadequate glue cure due to heavy glue spread, overwet veneer, sap wet spots, and short pressing time; and 5) combined effects of the above. It was found that veneer surface roughness had a significant effect on plywood gluebond quality, and excessive roughness and combined effect of veneer roughness, overdry, and glue dryout, were key causes of the low percentage wood failure. A statistical model was also developed from mill trials to predict the percentage wood failure in terms of veneer temperature, open assembly time and glue spread. The model helps establish an operating window for each key variable and adjust the gluing/layup process to reduce glue dryout. Furthermore, a practical method was developed to determine the optimum pressing parameters to achieve target gluebond quality while minimizing plywood thickness loss.
The project initially focussed on harvester transmission of staining fungi and insect transmission to logs in the forest and sawmill yard. Both harvesters and insects were confirmed to be major sources of bluestain infection. This work emphasized the importance of insect control measures in mill yards and a new project on mitigating harvester-related bluestain was recommended. Other related projects targeted potential control measures, such as sour-felling (crown drying) to reduce nutrients and moisture, biological control using albino fungi, and inventory control. Biocontrol work continued to be done under this project in 2005. We have assisted with the registration of a biocontrol agent and also examined the feasibility of developing a prototype harvester applicator system in collaboration with UBC mechanical engineering students. This spawned a separate project that looks into development of a spray applicator system on a commercial scale. In February 2004 and August 2005 we examined sources of bluestain in sawmills, such as air, sawdust and machinery. This work showed machinery as a possible mechanism for spreading bluestain from one piece of lumber to another during the milling. As each piece of work was completed, further data gaps were identified.
This report summarizes the progress from Year 3 of the multi-year Lumber Properties project. All activities continue to conform to the guiding principles adopted by the Lumber Properties Steering Committee (LPSC) at the start of the program. This year the first steps were taken in preparing information for discussion with the new American Lumber Standard Committee (ALSC) Lumber Properties Task Group (TG). Work continues on the review of the Norway spruce testing program and the development of an on-going monitoring program.
The program has enabled the wider industry group represented by the LPSC, to be involved in monitoring progress on the program and providing strategic direction. The support has also enabled the program to retain the necessary statistical support from the University of British Columbia to not only address Canadian lumber property issues, but also contribute to technical discussions at the ALS Lumber Properties TG.
Thermal treatments to improve the dimensional stability and durability of wood for exterior applications impart a pleasant dark brown colour but this rapidly fades to gray when exposed to weathering. A coating may solve this problem but adhesion to oil-thermal-treated wood may be an issue. The general objective of this research is to investigate the feasibility of coating oil-thermal-treated post-Mountain Pine Beetle (MPB) lodgepole pine for above-ground residential products such as siding. This is a continuation of previous research in 2006/07 on treating post-MPB lodgepole pine sapwood with oil-thermal treatment, also funded by FII. The current project focuses on surface modification and coating systems evaluation for this treated pine by laboratory tests, and initiating field tests for monitoring long-term coatings performance.
The project was carried out in collaboration with Dr. Paul Cooper of the University of Toronto, Dr. Phil Evans of the University of British Columbia, and Dr. Sam Williams of the Forest Products Laboratory of USDA. Based on the study carried out by FPInnovations–Forintek Division, Sikkens Cetol 123 and SuperNatural showed good adhesion on oil-thermal-treated pine, but the appearance of SuperNatural was preferable for the targeted applications. Hence, SuperNatural was selected for a long-term field test in Vancouver.
Based on the study undertaken by FPL, an aluminum isopropoxide sol-gel precursor was able to improve surface adhesion of the oil-thermal-treated wood for a water-borne finish, but did not improve the adhesion for solvent-borne finishes. The oil-thermal treatment did not appear to appreciably change the hardness or Young’s modulus of the wood based on the nano-indentation measurements. It was also found that the oil-thermal-treated wood could be easily treated with hydroxymethylated resorcinol (HMR), a coupling agent for coating. Its efficacy on coatings performance is being evaluated using an outdoor exposure test.
Based on the University of Toronto’s study, the oil-thermal treatment reduced the wettability of the wood to a number of solvents and had an adverse effect on coating curing and adhesion. Light sanding improved the wetting and resulted in improved adhesion. Among all the finishes evaluated, SuperNatural clear finish formed a hard coat with good adhesion.
The study by the University of British Columbia found that plasma treatment is able to remove oil from the surface of oil-thermal-treated pine, and increased its wettability as well as adhesion to coatings. Scanning electron microscopy, confocal profileometry, and Fourier transform infra-red spectroscopy also indicated that high-energy plasma treatment impacted wood structures, particularly around pits. The consequence of the plasma treatment on coatings performance is being studied with a weathering test.
Overall, the study showed that oil-thermal-treated blue-stained pine can be coated to improve weathering performance for exterior above-ground applications. It confirmed that sanding can improve the coatings performance. The effects of a coupling agent and plasma treatment on coatings performance are to be reported. Thermal modifications may provide a promising way to improve dimensional stability and also mask blue stain for post-MPB lodgepole pine. However, the potential bleeding of oil from wood with initially intense blue stain poses a major challenge for coating application and for developing residential appearance products from the post-MPB lodgepole pine using such an oil-thermal treatment. In that case, alternative thermal treatment processes, particularly using steam as the heating medium, could be considered.