The absence of commercial facilities to recycle or recover value from wood treated with metal-based wood preservatives at the end of its service life is one of the most significant negative points in the generally positive life cycle analysis of treated wood. Wood treated with carbon-based preservatives (metal-free) may be far easier to recycle or recover value from since the preservatives are relatively vulnerable to thermal, chemical and biological breakdown. As a result they might be destroyed by kraft pulping, combustion or composting of treated wood. The present research evaluates the use of carbon-based preservative-treated wood in these processes.
Kraft pulps produced from wood freshly treated with recommended loadings of carbon-based preservatives contained significant quantities of didecyldimethylammonium carbonate (DDAcarbonate), propiconazole and tebuconazole. However, lower preservative concentration in the wood and intensive pulping may be able to produce pulps without detectable preservatives. The azoles were also detected in significant quantities in the black liquor (DDAcarbonate was not analysed in black liquor).
No azoles were found in the ash produced from combustion, but significant quantities were detected in the filtered smoke. DDAcarbonate was not detected in the filtered smoke. Analysis of DDAcarbonate in ash was inconclusive.
A composting experiment has been set up and is in progress. Data on preservative breakdown during composting is expected next year.
To better understand the role extractives play in western red cedar’s decay resistance, commonly detected but unknown extractives need to be identified and evaluated for their potential contribution to natural durability. A new liquid chromatography/mass spectrometry (LC/MS) method for separating extractives from western red cedar has been developed. Mass spectral detection provides useful structural information that gives increased confidence in peak identifications and helps to identify unknown peaks. Using LC/MS data, combined with data from UV and NMR spectroscopy, unknown compound J commonly found in many samples of WRC we have analysed, was identified as alpha-thujaplicin. This was known to be a major extractive in eastern white cedar but was considered to be a negligible component of WRC. Its potential contribution to the durability of WRC has not been considered in previous work attempting to correlate durability to specific extractives.
The objectives of the project are to determine the major source of bluestain fungi and determine the mechanisms of their dispersion, and to determine the biology and weak points of pests that may be expoited to control them.
Le tronçonnage demeure pour la majorité des scieurs de bois feuillus un domaine problématique possédant un potentiel d’amélioration significatif, tant au niveau du volume sciable que du rendement valeur de la ressource disponible. La récupération de la valeur optimale d’une tige est directement liée à l’efficacité du préposé au tronçonnage. De mauvaises décisions de sa part résultent en une perte de valeur. Les principales raisons entraînant de mauvaises décisions sont la complexité et l’imprécision des lignes directrices, le grand nombre de classe de qualité, les exigences de productivité, le manque de formation et d’outils d’aide à la prise de décision. De plus, le nombre possible de combinaisons de longueur de billes et de découpes pour une même tige est assez important. L’évaluation d’une partie seulement des solutions potentielles requiert déjà un effort mental important.
Un système de tronçonnage complètement optimisé demeurera probablement une solution inaccessible pour la majorité des industriels à moyen terme. Cependant, la technologie des lecteurs et des caméras progressant très rapidement, il existe une possibilité de développer un système hybride qui pourrait générer des bénéfices importants. La ressource disponible est bien souvent de piètre qualité et il est envisageable de maximiser le volume de fibre sciable en optimisant le tronçonnage selon la courbure et la géométrie des tiges. Ce projet vise à chiffrer les bénéfices potentiels de cette approche de tronçonnage et d’en valider la faisabilité économique.
This report summarizes the progress from Year 4 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 support was provided to statisticians from the University of British Columbia’s Department of Statistics to meet and work with researchers and statisticians from the US Forest Products Laboratory (USFPL) in Madison, WI. All physical testing under the ongoing monitoring pilot study was also completed, allowing the UBC statisticians to continue work refining their global lumber properties simulator. Work is continuing on the collection of secondary properties for Norway spruce and on the analysis of the data collected to-date.
No activities requiring significant resources were carried out under the Resource Assessment and the Special Products Initiative. Instead, these resources were redirected to cover shortfalls in the provincial funding under the Strategic Framework Initiative, so that the statistical work with the USFPL could continue.
A research project was carried out in collaboration with researchers from both University of British Columbia and University of Toronto to develop and test a range of hollow core composite sandwich panels based on lignocellulosic materials that can extend the current applications of wood composite products such as high density particleboard and fibreboard (hardboard and MDF). With proper engineering design and unique light weight structural features, wood fibre resources will be more effectively used and the performance of each component can be maximized in these types of novel composite panels. The outcome of this project is the development of Canadian-made light weight panels containing various low density cores, including honeycomb, low density wood wool composites and cup-shaped thin fibreboard, and high density surface panels, including plywood, hardboard and high density fibreboard (HDF) for the applications in ready to assemble (RTA) modular furniture, home and commercial cabinetry and door panels.
The work completed at Forintek included:
Development of low density wood wool panels (LCD) as the core material for the sandwich panels.
Development of cup-shaped high density fibreboard (CHDF) as the core material
Evaluation of edgewise and flat compression strength and creep behaviour of honeycomb sandwich panels fabricated by UBC.
Development of book shelf panels using four different core materials.
Performance evaluation of the book shelves developed.
The results of the experimental work suggest that:
Low density composite core materials can be made by the technology developed at Forintek laboratory using low density poplar wood wool and high viscosity phenol and formaldehyde resin with steam injection hot pressing technology. However, the strength of the panels was relatively low comparing to conventional low density particleboard, OSB or fibreboard.
The experimental work carried out on the cup-shaped high density fibreboard (CHDF) show the potential for developing various light weight core materials using current MDF process technology. The internal bond strength (IB) and water absorption (WA) of the cup-shaped panels were strongly correlated with panel density. IB increased and WA reduced when increasing the panel density. The flexibility of the technology could optimize the properties and performance of CHDF through manipulating the fibre refining process, profile design, resin system and hot pressing strategy. It shows that CHDF is a good alternative material to Kraft paper honeycombs for the manufacture of sandwich panels for higher strength and performance applications.
Test results from sandwich panels made of cup-shaped fibreboard core and HDF surface show that the nominal density of the cup-shaped core was one of the most important process parameters to adjust for the improvement of the sandwich panel properties. The flat compressive modulus, flat tensile strength and short-beam strength increased when increasing the nominal density of the core panels. Furthermore, the overall density of the sandwich panels were only fractionally increased by increasing the nominal density of the core panels due to the cup-shaped shape of the core panels. It suggests that higher nominal core density should be used when higher mechanical strength of the panels is required.
To a lesser extent, fibre type in the core panels also affects the sandwich panel properties. Longer wood fibres are recommended for use in the manufacture of the core panels.
The results of the experiment also show that increasing the thickness of the surface HDF panels increased the bending strength of the sandwich panels substantially. However, the overall density also increased.
Comparing shear properties of the four different sandwich panels developed by Forintek, we can identify that the ultimate shear strengths were different for different core materials. The sandwich panel made from polycarbonate core had the highest shear strength (0.744 MPa) followed by the panel made with CHDF (0.497 MPa). The sandwich panel made from low density wood wool core had much lower shear strength (0.012 MPa) which is lower than the paper honeycomb sandwich panels previously made by UBC with the same surface and core thickness (0.024 MPa).
The sandwich panels made with high density cup-shaped fibreboard had significantly higher core shear modulus (92.0 MPa) than any other sandwich panel studied in this project.
This is a discussion paper addressing the factors involved when considering the total environmental footprint of wood doors. The discussion is within the context of a new amendment to BC energy regulations affecting doors and the subsequent market shifts that will occur as a direct result. The energy regulation applies a U-value threshold to doors. U-value is a physical (thermal) property of an assembly indicating the rate of conductive heat flow through the assembly. A maximum U-value for doors is being specified in BC that cannot be met by the current commonly-manufactured configuration for solid wood doors. In this paper, a life cycle assessment (LCA) approach is used to discuss the broader environmental picture beyond the single criterion of U-value, specifically focusing on the trade-off between embodied energy in a product and the impact of that product on the operating energy of the building in which it is installed. Any change to the current manufacturing process for wood doors for the purpose of improving thermal characteristics should be done within an LCA perspective so that the changes don’t inadvertently lead to a net increase in total lifetime energy consumption. Similarly, any market shift to non-wood alternatives for doors should also be done within an LCA perspective for the same reason. A detailed and precise analysis of door footprints requires LCA data and energy simulation results, both of which are beyond the scope of this study. In place of full LCA data, we accessed existing literature and existing partial LCA data (from the Athena Institute) to roughly estimate the embodied energy differences between door types, and to discuss the other environmental impacts of a substitution from today’s common wood doors to non-wood alternates. Three generic door types were compared: wood, steel and fibreglass. In all the environmental metrics examined, including embodied energy, the wood doors have the lowest impact. Although insulated steel and fibreglass doors typically have a lower U-value than wood doors, they involve more energy consumption in their manufacturing. This means that the added energy investment in steel and fibreglass doors will require some time to be paid back through reductions in a home’s heating and cooling costs. Similarly, an improvement to wood doors to reduce U-value may increase the embodied energy, requiring a payback period that may or may not be reached within the lifetime of the door.
Softwood and hardwood logs and lumber are susceptible to sapstain from the time the tree is felled, during storage prior to processing, and after processing. As part of the project, Biology and Management of Bluestain, we aim to help the industry to extract the most value from wood by finding ways to prevent bluestain and other biodeterioration during wood storage and transport. Recently we investigated the feasibility of using controlled atmosphere storage to inhibit the growth of sapstain fungi. This involves wrapping and sealing green logs or lumber immediately after harvesting in UV-resistant and gas-impermeable sheets. This allows CO2 to build up to 20-40% due to microbial and live wood cell respiration, while oxygen gets depleted to near zero levels in a few days. This ecologically friendly storage method does not depend on climate, storage site, tree species or size of pile. It may be used in areas where other methods are not available and in nature-conservation, water protection and other ecologically sensitive areas. Logs have been shown to remain sound for up to four years. The process has been patented in Germany and has been used in Europe on a commercial scale but has limited exposure in North America. This paper reviews existing knowledge and experience with this process and assesses the feasibility of using it in Canada for Canadian wood species. It also aims to recognize key knowledge gaps that may need to be addressed before the method is presented to the industry as a viable and economical option for safe storage of wood on a large industrial scale.