La portée de l'information contenue dans ce document donne au lecteur une compréhension approfondie de l'écologie forestière, des caractéristiques, de la transformation et des usages des principales essences commerciales de résineux de l'Est du Canada. Si la partie sur l'écologie forestière vise à donner aux professionnels du bois une connaissance de base de chaque essence, les autres parties donnent de l'information complète sur différentes propriétés et caractéristiques du bois, sur les possibilités de transformation primaire et secondaire et sur différents usages.
Le manuel donne à l'industrie du bois, pour chacune des essences qui y sont abordées, un outil de référence de qualité qui lui permettra de gérer, de traiter et d'utiliser efficacement chaque essence et d'ajouter de la valeur à la chaîne de valeur du bois en forêt "de la graine jusqu'au produit, en passant par l'arbre".
Cette publication sera également utile aux lecteurs suivants :
- Aménagistes forestiers : en présentant de l'information exhaustive sur les effets des pratiques sylvicoles sur plusieurs caractéristiques et usages du bois.
- Professionnels de la forêt et du bois : comme outil de référence indispensable leur permettant d'acquérir une parfaite connaissance des essences avec lesquelles ils travaillent au quotidien.
- Organismes gouvernementaux : en fournissant l'information utile à la définition de politiques et de règles rigoureusement scientifiques sur l'aménagement forestier.
- Grand public : en l'aidant à mieux comprendre la valeur économique des résineux de l'Est en tant que ressource renouvelable et à mieux apprécier leur contribution à la viabilité économique.
L’industrie canadienne des lames de plancher utilise actuellement différents types de contreplaqués comme substrat dans ses constructions de LPI (lames de plancher d’ingénierie). Les contreplaqués finlandais et russes sont particulièrement utilisés. Cependant, des problèmes d’approvisionnement et de qualité sont connus chez les producteurs russes alors qu’un coût très élevé est associé au produit finlandais.
L’objectif principal de ce projet est de développer un panneau OSB spécial en vue d’être utilisé comme substrat dans la fabrication des lames de plancher d’ingénierie.
Le projet compte deux étapes principales. Les qualités d’un produit OSB pour la fonction de substrat LPI sont la rigidité du panneau, la cohésion interne et la stabilité dimensionnelle en épaisseur. En conséquence, nous avons développé, dans un premier temps, des formulations d’OSB tenant compte de ces qualités. Deux types de lamelles de bois ont été sélectionnés pour être utilisés dans la fabrication de panneaux OSB (cœur et trituration) :
1. un mélange de 90% de peuplier faux-tremble (Populus tremuloides) et 10% de bouleau à papier (Betula papyrifera);
2. 100 % de pin ponderosa (pinus ponderosa).
Une expérience factorielle a été utilisée pour évaluer l’effet de trois facteurs sur les propriétés de panneaux. Les facteurs choisis ont été la teneur en adhésif (trois niveaux), le profil de densité (deux niveaux) et le rapport entre les couches de surface et la couche médiane (trois niveaux). Trois répétitions de ce dispositif ont été réalisées de manière à pouvoir appliquer une analyse de variance (ANOVA). Afin de choisir les meilleures combinaisons pour notre application, des tests de flexion, de cohésion interne et de gonflement ont été effectués pour chaque type de matériaux.
Dans le deuxième volet du projet, des prototypes de lames de plancher d’ingénierie ont été fabriqués en utilisant comme substrat : l’OSB grade sheathing, l’OSB web stock, le contreplaqué russe et les deux types de panneaux OSB spéciaux. Ces prototypes ont été testés dans la chambre climatique. Des différences non-significatives ont été observées entre LPI faites en utilisant comme substrat les contreplaqués et les panneaux spéciaux. Les résultats obtenus démontrent la faisabilité d’utiliser le panneau OSB comme substrat dans la fabrication de lames de plancher d’ingénierie.
Bluestain reduces the value of wood in appearance applications where the natural wood colour is desired. Treatments that remove bluestain without degrading the natural colour of the wood could make this lumber more suitable for appearance-grade applications.
FPInnovations and UBC have each previously developed methods of decolourising bluestain but both resulted in unacceptable colourations in the wood (Binnie et al., 2000; Evans et al., 2007). Follow up work at FPInnovations found that the combination of hypochlorite bleaching and exposure to UV and visible light was able to remove bluestain from lodgepole pine (Stirling and Morris, 2008). The present work identified the minimum treatment times required for effective bluestain removal to be a 10 minute bleaching dip and 10 minutes of exposure to intense light. Near- and mid-infrared spectra indicated changes in surface chemistry after treatment. However, adhesion tests showed no signs of reduced coating adhesion caused by UV damage or hypochlorite exposure.
The overall objective of this project is to maximize the value of Canadian cedars by identifying the strengths and limitations of their natural durability and improve the quality of Canadian cedar products by maintaining and enhancing natural durability.
In Report #1 the fixative agents found to inhibit leaching of western red cedar (WRC) extractives were evaluated for their ability to improve the decay resistance of WRC against a brown rot and a white rot fungus in a soil block test without acting as biocides. Two of the treatments were found to reduce weight loss of WRC by the brown rot fungus Coniophora puteana but did not affect weight loss of ponderosa pine. Fixative efficacy against the white rot fungus, Irpex lacteus, could not be determined because the fungus did not cause significant weight loss in the untreated western red cedar control. Further work is planned to evaluate the field performance of these treatments and to evaluate the performance of coatings on western red cedar treated with these fixatives.
Report #2 describes a new liquid chromatography/mass spectrometry (LC/MS) method for separating extractives from western red cedar. 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 that 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. Continuing LC/MS development will lead to a determination of the abundance of alpha-thujaplicin in the western red cedar resource, new methods for the analysis of heartwood extractives from yellow cypress and eastern white cedar, and further characterization of unknown peaks in western red cedar.
In other work, not included in these reports, initial attempts were made to correlate field test ratings for western red cedar, eastern white cedar and yellow cypress with extractives data. No correlations were evident with four-year data from two test sites, largely because the ratings did not vary much. This will be re-visited after the five-year data from all sites are available and reported at that time.
An experiment was set up to identify fungi capable of detoxifying western red cedar. WRC and ponderosa pine (control) blocks were stored in ground contact for six months and above ground for one year and sampled regularly to measure extractive concentration and to isolate potential detoxifier fungi. Fungal identification is underway and a soil block test against decay fungi is planned to determine whether extractive loss affects decay resistance.
To assist in the transformation of the industry, FPInnovations’ Durability and Protection Group required significant investments in research infrastructure to speed up the research process. With funding from the Transformative Technologies program, FPInnovations has upgraded its capabilities in the area of rapid above ground preservative testing, rapid fungal identification and rapid biocide detection and characterization. Work has been initiated to assess the potential advantages and to understand and mitigate the potential disadvantages of transitioning to carbon-based preservative systems.
In North America, the voluntary withdrawal of chromated copper arsenate (CCA) from most residential uses in January 2004 resulted in a burgeoning development of wood preservatives likely to be perceived by the general public as more environmentally and health friendly. The initial shift was to copper-based preservatives with carbon-based co-biocides to control copper tolerant brown-rot fungi. These typically contain three times as much copper as CCA and the absence of chromium means that copper is not as well fixed in the wood. Early formulations (much prior to 2004) had used ammonia as a copper solvent but the ammonia off-gassing proved problematic and copper-amine systems were introduced. The ethanolamine is not a fugitive solvent like ammonia, consequently the copper in these preservative systems is more readily available to leach out and cause staining, corrosion and potentially adverse impacts on aquatic environments. Most of these problems can be overcome by careful formulation, treatment and post-treatment conditioning; however, at least one jurisdiction, the Netherlands, has eliminated use of copper-based preservatives. Wood preservative manufacturers have therefore developed the first generation of entirely carbon-based preservatives. These are currently going through the process of registration by Health Canada’s Pest Management Regulatory Agency (PMRA). It is highly likely that further development of these preservative systems will result in reduced susceptibility to biodegradation and improved performance. As seen with copper-based preservatives, we can expect to see a second and likely a third generation of carbon-based preservatives.
The PMRA requires performance data on Canadian wood species under Canadian conditions, including failure of low preservative retentions, prior to registering new preservatives. This can take seven to ten years using existing standardized field tests for above ground applications. The first report in this compilation describes the construction of an Accelerated Field Simulator (AFS) for rapid evaluation of the decay resistance of preservatives exposed above ground.
While there is a plethora of information on fungi capable of detoxifying or tolerating copper, and those which cause premature failure of copper-treated wood in service, there is relatively little information on the fungi which are likely to limit the performance of carbon-based preservatives. The AFS is designed to expose treated wood to spores of known decay fungi but also to natural airspora from outdoor air. This is anticipated to permit colonization of wood-treated with carbon-based preservatives by fungi that are capable of preservative detoxification or tolerance. Rapid identification of these fungi is important in the investigation of biodegradation of carbon-based preservatives and in the selection of appropriate fungi for laboratory tests. Using traditional morphological techniques is an extremely time consuming process and most laboratories now use modern molecular methods. Report number 2a in this compilation describes the selection, acquisition and commissioning of a molecular identification system for fungi based around Polymerase Chain Reaction (PCR) technology. Report number 2b is a draft paper on the use of this technology to confirm that the fungi growing on wood treated with carbon-based preservatives in the prototype accelerated above ground test must have colonized by spore germination and were the same species as the fungus fruitbodies installed in the chamber.
Most Canadian wood species can not be fully penetrated by pressure treatment with waterborne formulations. This has not proved to be a problem with copper-based preservatives because the copper is able to move into untreated surfaces freshly exposed when wood checks and prevent the germination of basidiospores. The omission of copper requires that other means are found to ensure performance in Canadian species which can not be treated all the way through. It is therefore important to know as much as possible about the initial distribution of the carbon-based preservatives, their mobility, redistribution and possible biodegradation in the wood. FPInnovations had developed methods for the extraction and analysis of the most commonly used carbon-based preservatives using High Performance Liquid Chromatography, but this was not capable of detecting low biocide loadings or characterizing biocide breakdown products. The third report in this compilation describes the identification, acquisition and commissioning of Liquid Chromatography-Mass Spectroscopy technology, which will enable detection of low preservative loadings and enable the chemical characterization of breakdown products.
An MSc student has been recruited to explore the mobility of the carbon-based preservatives, their ability to coat the untreated wood exposed in checks and their effectiveness in preventing germination of basidiospores. Report number 4a is the student’s thesis proposal and report number 4b covers the results of a directed study on detoxification of triazoles by wood decay fungi. Two wood-rotting basidiomycetes used in standard tests were found to be capable of detoxifying tebuconazole.
Currently, end of service life issues are the major Achilles heel of treated wood products due to the difficulty of extracting copper from the wood. The major benefit of the omission of copper from the carbon-based preservative systems is the potential to recycle or recover value from the treated wood with no detectable contaminants. Industry’s ability to confidently transition to these new preservatives and improved consumer perception of wood that can be readily recycled will ensure that wood retains markets currently under threat from non renewable materials with considerably higher energy consumption. The fifth report in this compilation covers the recycling of treated wood at the end of its service life. Kraft pulping, burning and composting of wood treated with carbon-based preservatives were investigated. All of the carbon-based preservatives evaluated survived kraft pulping. Analysis of combustion residues and compost is on-going.
The data generated in this project will provide an indication of the time required for initiation of strength loss in wood-based panels when the panels are exposed to a range of fluctuating moisture contents and temperatures.
The objectives of the project are to develop two-way technology transfer instruments that achieve a connection with specifiers, designers, builders, homeowners and maintenance supervisors and to explore opportunities for collaborative field studies of durability performance where information gaps exist.
Bluestain in wood can cause serious economic losses to the forest industry and may be, or be perceived as, a phytosanitary risk. The fungi causing Bluestain are commonly referred to as Ophiostomatoid fungi and include species of Ophiostoma, Grosmannia, and Ceratocystiopsis, from the order Ophiostomatales, as well as some species in Ceratocystis in the order Microascales. Many of these fungi are morphologically similar and cause similar symptoms, which makes traditional identification difficult. Identification and/or detection of these fungi are commonly done using molecular methodology. An understanding of the causal organism is necessary in the management of bluestain on forest products; therefore a review of the molecular work done in terms of classification, identification and detection on these fungi was undertaken in order to produce a reference guide for future identification/detection of bluestain fungi using molecular technology.
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.
In the mid 1990s, FPInnovations - Forintek Division (then known as Forintek Canada Corp.) initiated a study of borate-treated lumber above ground, protected from rain but exposed to termites in Kincardine, Ontario and, in collaboration with other researchers, in Japan and Hawaii. The material included hemlock and amabilis fir lumber treated with borate and chromated copper arsenate (CCA). Reference materials included Hinoki in Japan, ACZA treated Douglas-fir in Hawaii and western red cedar in Canada. The samples were evaluated annually for termite attack. Generally in Canada all of the treated material was found to be performing equally well, with some pieces showing residual signs of earlier superficial feeding or cosmetic damage. Attack was moderate on untreated controls. This was also the case in Japan with the exception of 2% borate shell treatments with DDAC in which two samples were rated as moderately or severely attacked. In Hawaii, where termite attack was more severe, CCA and 3% borate through treatments performed better than the others.
After ten years of exposure, the tests in Japan and Hawaii were terminated and the test samples were returned to Forintek. The Hawaii samples, which had suffered more termite damage than those from Japan, were examined by Forintek’s CT scanner to determine the extent of internal damage not detectable by a visual rating of the pieces. This revealed that the 3% through borate treatments contained the least termite damage though 2% through borate treatments had negligible attack. The borate treated pieces returned from Hawaii were also subjected to measurements of compression stiffness at seven points along their length. Results showed that the stiffness of any specimen was similar along its length. Only the 2% shell treated samples showed statistically significantly lower stiffness than the 3% through treated samples which had no internal damage.
Five borate-treated dodai from each group returned from Hawaii and Japan were destructively sectioned for analysis of residual borate. Patterns of borate distribution were plotted. Generally, the amount of borate retained was less on the outer surfaces (top, sides, and bottom). There did not appear to be a correlation between the treatment type (i.e. shell or through, 2% or 3%) and the percentage of borate retained, nor between the rating given the piece for decay and the percent of borate retained.
In summary, ten-year results of field exposure in Hawaii and Japan, in relatively aggressive termite feeding situations, support the conclusion that borate treatments, as well as CCA and ACZA treatments, can provide long-term protection from destructive termite attack to structural lumber. A 3% BAE through-treatment performed comparably to CCA treated hem-fir in Japan and Hawaii. Plantation-grown Hinoki showed termite attack at the same rate as untreated hemlock.
After five years of exposure in a field test in southwestern BC, second growth western red cedar shingles treated with waterborne preservatives alternative to CCA-C are in excellent condition, with no visible decay. Untreated shingles are also still in very good condition.
A field test of untreated and preservative-treated round fence posts has been ongoing at Petawawa, ON since 1937. Service life data on untreated posts of 20 eastern Canadian wood species were developed. In addition, treatments by a variety of pressure and non-pressure processes with waterborne and oilborne preservatives were tested. Thermal immersion in creosote was the most effective non-pressure method used, while brush treatments and cold soaking proved to be ineffective for long-term protection from decay. Pressure treatment using standard waterborne (CCA and ACA) and oilborne (creosote, pentachlorophenol, copper naphthenate, and oxine copper) preservatives provided excellent protection.
Transformative Technologies - Element I identifierSeries Progress Report 2009/10i
Project No. 201000356
W-2695
Location
Vancouver, British Columbia
Language
English
Abstract
Some black stain fungi are known to exhibit resistance to carbon-based preservatives. However, the cause of this resistance is unclear. The fungi may have mechanisms to tolerate these chemicals, or they may be able to degrade and detoxify them. Fungi capable of degrading carbon-based preservatives are of interest for possible bioremediation of carbon-based preservative-treated wood at the end of its service. Moreover, such fungi could potentially facilitate the colonization of carbon-based preservative treated wood by decay fungi. Two strains of Aureobasidium pullulans and two strains of Epicoccum purpurascens were evaluated for their ability to degrade three commonly used carbon-based preservatives: propiconazole, tebuconazole, and DDAC. At low and medium concentrations propiconazole and tebuconazole were found to be vulnerable to degradation by one of the Epicoccum purpurascens isolates. Where biocides are needed to control the growth of black stain fungi on wood, a combination should be used to minimize the risk posed by resistant strains.
This research project aims at defining the needs of hardwood users of secondary and third transformation. Information was gathered from twenty-seven businesses that agreed to see us at their plant or to discuss over the phone. We included the following industrial sectors: flooring, kitchen cabinets, furniture, pallet, moulding, turning, coffins, doors and windows. The data covers the three facets of user needs: supply, manufactured component sizes and the quality of manufactured components.
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.
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.
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.
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.
