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Croissance, propriétés et utilisations du Western Red Cedar

https://library.fpinnovations.ca/fr/permalink/fpipub38910
Auteur
Gonzalez, J.S.
Date
March 2004
Genre du document
Research report
Domaine
Sustainable Construction
Auteur
Gonzalez, J.S.
Date
March 2004
Genre du document
Research report
Description physique
42 p.
Secteur
Wood Products
Domaine
Sustainable Construction
Champ de recherche
Advanced Wood Materials
Sujet
Wood quality
Wood
Thuja plicata
Quality control
Qualitative analysis
Physical properties
Growth
Série
E-3969
Localisation
Vancouver, British Columbia
Langue
French
Résumé
Le Western Red Cedar est un arbre très répandu sur la côte Nord-Ouest du Canada et des États-Unis et dans les forêts pluviales de l'intérieur de la Colombie-Britannique (C.-B.). Cet arbre constitue l'une des essences résineuses les plus anciennes en Amérique du Nord et les plus résistantes à l'altération par les champignons ou les insectes. C'est pourquoi il peut atteindre une très grande taille. Depuis des temps immémoriaux, les Premières nations de la région du Nord-Ouest ont utilisé le bois, les branches, l'écorce et les racines du Western Red Cedar à des fins rituelles ou religieuses, ou dans la fabrication de maisons, de moyens de transport, de vêtements, d'objets domestiques ou d'accessoires de pêche ou de chasse. Mesurée en volume de bois debout, la présence des Red Cedars en C.-B. représente environ 750 millions de mètres cubes. Plus de la moitié de ces arbres se trouvent dans la région côtière, où ils se classent au deuxième rang parmi les conifères les plus répandus, la majeure partie de la côte se composant d'anciennes forêts, c'est-à-dire vieilles de plus de 250 ans. À eux seuls, les parcs ou d'autres zones protégées abritent quelque 50 millions de mètres cubes des Red Cedars présents dans la région côtière. Une portion notable de ces Red Cedars se trouve également dans la "forêt exploitable" de la Côte, dont une grande partie a obtenu, ou obtiendra bientôt, sa certification environnementale. Les jeunes plants de Red Cedar commencent à prendre de la maturité et, avec les Red Cedars plus anciens, sont exploités pour la grande valeur de leur bois. La quantité de Red Cedar exploités tourne autour de six millions de m3 par an, soit une quantité jugée écologiquement soutenable, compte tenu de la possibilité de coupe pour l'ensemble de la province. Le Western Red Cedar est un bois léger, de texture uniforme, de fil droit et dépourvu de résine. Ces caratéristiques en font un excellent bois d'oeuvre et une essence très recherchée pour les applications exigeant une résistance à l'altération par les champignons, une stabilité dimensionnelle ou un bon pouvoir isolant. Ce bois se prête à de nombreuses utilisations telles que la fabrication de revêtements extérieurs, de terrasses, de clôtures, d'accessoires de jardin, de rondins traditionnels ou de lamellés pour l'industrie de la construction, de poteaux de services publics, et de produits de spécialité tels que panneaux de revêtement intérieurs, instruments de musique et bardeaux de toit (souvent faits à partir de troncs d'arbres morts trouvés dans la forêt). Même si seuls les déchets de scierie sont employés dans la fabrication de la pâte à papier, l'excellente morphologie du Western Red Cedar est recherchée dans la production de pâte kraft pure ou mélangée, aux fins de fabrication de produits de papier pour usages spéciaux. Le Western Red Cedar a fait l'objet de nombreuses études scientifiques, particulièrement en ce qui a trait à ses propriétés chimiques exceptionnelles. Les matières extractibles contenues dans le bois de coeur agissent sur les caractéristiques de celui-ci dans une proportion bien supérieure à la quantité de matière présente. Ces matières extractibles donnent au bois son caractère particulier, et celles qui confèrent au Red Cedar sa grande durabilité font actuellement l'objet d'importantes découvertes. Des recherches sont présentement effectuées sur les utilisations possibles de l'huile de bois et des matières extractibles purifiées du bois. En Colombie-Britannique, on procède depuis 1987 à l'extraction et à la vente de l'huile des feuilles. Des recherches se poursuivent sur l'interrelation entre le taux de croissance, la densité et la durabilité du bois selon qu'il est soumis à différentes pratiques sylvicoles. Les données indiquent que la densité du bois de Red Cedar à croissance rapide est moindre que celle du bois ancien, mais cela n'affecte pas son utilité, étant donné qu'il sert principalement à des fins décoratives ou à la fabrication de produits non structuraux. Les recherches sur la durabilité du Red Cedar de seconde génération sont en cours, et tout semble indiquer que les matières extractibles contenues dans les jeunes arbres vigoureux de seconde génération sont beaucoup plus abondantes que celles présentes dans le bois de coeur des Red Cedars que l'on retrouve dans les forêts anciennes de même âge depuis la germination des graines. Cela est probablemetn attribuable en grande partie au fait que les microorganismes présents dans les arbres anciens sur pied finissent par dégrader les matières extractibles. Le Western Red Cedar constitue l'un des arbres les plus étudiés du monde entier. Ce document fait le point sur les connaissances actuelles concernant cette essence et traite de la croissance, des propriétés et des utilisations du Western Red Cedar.
Thuja plicata - Physical properties
Growth - Influence on quality
Growth - Influence on physical properties
Wood quality
Documents
Moins de détails

Development of fibreboard for outdoor applications

https://library.fpinnovations.ca/fr/permalink/fpipub42272
Auteur
Deng, James
Date
August 2004
Genre du document
Research report
Domaine
Wood Manufacturing & Digitalization
Auteur
Deng, James
Date
August 2004
Genre du document
Research report
Description physique
34 p.
Secteur
Wood Products
Domaine
Wood Manufacturing & Digitalization
Champ de recherche
Advanced Wood Manufacturing
Sujet
Research
Série
General Revenue 4006
4006
Localisation
Sainte-Foy, Québec
Langue
English
Résumé
The goal of this project, carried out at Forintek’s Quebec MDF Pilot Plant, was to develop an enhanced fibreboard product for exterior applications. The experimental work consisted of three different phases. Phase I consisted of selecting a suitable resin system from among five types of resin exposed to the same process conditions. Panels produced with the MUPF resin (resin R03) had the best overall moisture resistance and dimensional stability properties. Phase II defined optimal refining and hot pressing process conditions. Based on the experiment results and statistical analysis, a numerical optimization was carried out using Design Expert® computer software. Phase III examined the chemical modification of wood fibre by acetylation. The following conclusions can be reached from this research project:
Among the five different resin systems, resin R03 (an MUPF resin) produced the best overall panel properties for moisture resistance and dimensional stability and was most cost effective.
For resins R03 and R04 (MUF), post-press heat treatment showed marginal improvements in panel bonding strength, moisture resistance, and dimensional stability.
Panels made with MDI resin were comparable to R03 panels in terms of dry IB, but resulted in lower water resistance (lower one-hour boiling IB).
With resin R03, panel series S7 had the best overall panel properties among the 8 different types of panels made under the different process conditions.
Resin content of R03 in the panel had the greatest effect on IB, water resistance, and dimensional stability.
Higher steam temperature in the preheater improved panel moisture resistance and dimensional stability.
All properties tested in S7 produced results higher than those typical of wood plastic.
The cost to produce S7 is about 40% of the cost of wood plastic panels for similar applications.
Acetylated wood fibre demonstrated a great improvement in water resistance and dimensional stability. However, further research is required in order to find better adhesives and application methods to optimize MDF panel processes with acetylated fibre.
Wood fibre-based panel can replace wood plastic for exterior applications at a significant cost advantage.
Further work is required to optimize the process and to fully evaluate panel properties under long term outdoor conditions.
Fibreboard - Research
Fibreboard - Manufacture
Documents
Moins de détails

State of knowledge on limiting conditions for decay

https://library.fpinnovations.ca/fr/permalink/fpipub41308
Auteur
Clark, Jean E.
Morris, Paul I.
Date
September 2004
Genre du document
Research report
Domaine
Sustainable Construction
Auteur
Clark, Jean E.
Morris, Paul I.
Collaborateur
Canada. Canadian Forest Service.
Date
September 2004
Genre du document
Research report
Description physique
13 p.
Secteur
Wood Products
Domaine
Sustainable Construction
Champ de recherche
Advanced Wood Materials
Sujet
Wood
Wood decay
Mechanical properties
Strandboards
Physical properties
Plywood
Oriented strandboard
Orientation
Série
Canadian Forest Service No. 16;1963
W-2104
Localisation
Vancouver, British Columbia
Langue
English
Résumé
The wood industry is facing some serious challenges in how end users view the long-term reliability of wood construction systems. The 1990s have seen the industry hit with a series of high-profile wood product failures due to decay, for example in North Carolina and coastal British Columbia. There are several efforts underway in North America and around the world focused on developing predictive models for moisture conditions in exterior wall systems. All of these models can predict temperature and wood moisture content change over time, but the consequences of those conditions in terms of decay are not yet predictable. While it is known that wood below 20% moisture content will not decay and wood above 28% moisture content will decay, fungal response to conditions between 20 and 28% is not well documented, particularly for North American fungi and wood species. Forintek Canada Corp. has a project underway to determine the time required for wood products to suffer detectable strength loss under a variety of temperature and moisture conditions. The focus is on sheathing as it is the last place to dry out after wetting events. Since this project was initiated, other researchers have become involved in this issue and it is therefore timely to review the state of the knowledge in this area. There is a considerable volume of work published and a limited amount of work underway but little of this is directly relevant to developing damage functions for hygrothermal models. The work underway at Forintek needs to be completed to define the time to initiation of decay under constant moisture conditions. Further work needs to be done to define the time to initiation of decay under fluctuating conditions. Data on the initial rate of decay under limiting conditions should also be generated from this work.
Buildings - Decay
Fungi - Wood destroying
Strength - Influence of moisture content
Plywood - Strength
Oriented strandboard - Strength
Documents
Moins de détails

Update on international durability research. Progress Report 2004/05

https://library.fpinnovations.ca/fr/permalink/fpipub41315
Auteur
O'Connor, J.
Date
March 2005
Genre du document
Research report
Domaine
Sustainable Construction
Auteur
O'Connor, J.
Collaborateur
Canada. Canadian Forest Service.
Date
March 2005
Genre du document
Research report
Description physique
25 p.
Secteur
Wood Products
Domaine
Sustainable Construction
Champ de recherche
Advanced Wood Materials
Sujet
Research
Série
Canadian Forest Service No. 19;1052
W-2130
Localisation
Vancouver, British Columbia
Langue
English
Résumé
This year-end report for the continuing project “Decision Aids for Durable Wood Construction” focuses on international activity in building envelope research. One of the major task areas within Decision Aids is knowledge maintenance about related work elsewhere; 2004/2005 was a particularly active year for building science conferences, which are the primary venue for research reporting in this field. Short summaries of current work are provided, organized by institution. In addition, the other activities under Decision Aids are also reported, including an expansion of the durability web site and an update on the proposal for an outdoor test facility in Vancouver.
Research - Durability
Documents
Moins de détails

NSERC innovation : hybrid structural wood composites for non-residential construction

https://library.fpinnovations.ca/fr/permalink/fpipub41325
Auteur
Pirvu, Ciprian
Date
March 2005
Genre du document
Research report
Domaine
Sustainable Construction
Auteur
Pirvu, Ciprian
Collaborateur
Natural Sciences Engineering Research Council
Date
March 2005
Genre du document
Research report
Description physique
10 p.
Secteur
Wood Products
Domaine
Sustainable Construction
Champ de recherche
Building Systems
Sujet
Mechanical properties
Research
Physical properties
Materials
Série
W-2197
Localisation
Vancouver, British Columbia
Langue
English
Résumé
In recent years, significant attention has been paid to the engineering performance of wood structural systems, and a new generation of more reliable engineered wood components for building construction has evolved. The latest trend is towards advanced products that combine wood and synthetics. This increases performance and structural reliability of engineered wood products, and leads to new markets and expanded opportunities. It is anticipated that cost of fibre reinforcement decreases over time and advances developed on reinforcing techniques and methods of evaluation would provide wood producers with more options to better position their products in the marketplace. A new reinforcing technique has been developed and applied to manufacture a hybrid wood product for structural applications. The technique involves a layering analogy using layers of synthetic reinforcement sandwiched between layers of wood composite. The products manufactured in the laboratory used regular OSB laminations and alternating layers of E-glass fabrics and resin. Three- and four-ply billets were manufactured with various layouts and then tests were conducted to characterize mechanical properties of the hybrid products. Overall, the test specimens performed well relative to the controls. Shear failures were observed as a result of the limited performance of OSB in shear, and consequently the next tests will be conducted with plywood laminations instead of OSB. Selected issues related to code acceptance of structural FRP-reinforced wood products are discussed in the appendix. Future work is suggested to completely characterize and understand the properties and behaviour of the FRP-reinforced wood products, including fire performance, long term durability, maintenance and cost, in order to establish an environment in which to work comfortably with such materials. Overcoming these issues is vital for product acceptance in building codes.
Composite materials - Physical properties
Composite materials - Research
Composite materials - Strength
Documents
Moins de détails

Establishing the optimum panel densification for performance plywood/LVL products - new method developed to measure veneer quality and bondability. Final Report 2004/05

https://library.fpinnovations.ca/fr/permalink/fpipub37729
Auteur
Wang, Brad J.
Date
April 2005
Genre du document
Research report
Domaine
Wood Manufacturing & Digitalization
Auteur
Wang, Brad J.
Date
April 2005
Genre du document
Research report
Description physique
36 p.
Secteur
Wood Products
Domaine
Wood Manufacturing & Digitalization
Champ de recherche
Advanced Wood Manufacturing
Sujet
Veneer
Testing
Mechanical properties
Physical properties
Plywood
Laminate product
Grading
Automatic control
Série
General Revenue Report Project No. 3901;3901
W-2158
Localisation
Vancouver, British Columbia
Langue
English
Résumé
In this study, extensive veneer compression tests were conducted to examine the transverse compression behaviour of veneer at both ambient and controlled temperature and moisture content (MC) environments. Based on the results, a novel method was developed to characterize overall surface quality of veneer and other wood materials in terms of their bondability and compression behaviour. The method would have significant implication in both theory and practice. In theory, the general wood compression theory would need to be modified. The revised wood compression theory would include four stages instead of commonly defined three. The first stage, which has long and so far been overlooked but is critically important, could be named as “non-linear conformation”. During this stage, the contact area increases nonlinearly with the load applied. It is this stage that directly reveals the interfacial bonding behaviour of wood materials such as veneer-to-veneer and strand-to-strand and their minimum compression required for achieving adequate contact (bonding). In practice, the method provides a fast and objective way of evaluating surface roughness/quality of veneer and other wood materials. The new method also establishes the maximum compression allowable for achieving the best panel performance in terms of bonding strength, stiffness and dimensional stability. Based on the concept of this method, it was further found that both minimum compression required and maximum compression allowable are independent of temperature and MC, which provides a direct benchmark to the material recovery during panel hot-pressing. In a case study with Trembling aspen veneer, the variation of veneer surface roughness/quality and its effect on resulting material recovery were first revealed. Then, the optimum panel densification was identified for performance plywood and LVL products based on the frequency distribution of the minimum compression required and the maximum compression allowable. Finally, an overall veneer quality index was established to compare veneer overall quality for different species/thickness. The method shows good potential in practical applications for increased material recovery, reduced glue consumption and improved panel performance.
Veneers - Strength - Tests
Plywood - Strength - Tests
Lumber, Laminated veneer - Strength - Tests
Grading - Automation
Documents
Moins de détails

The effect of extractives on equilibrium moisture content in western redcedar

https://library.fpinnovations.ca/fr/permalink/fpipub41321
Auteur
Stirling, Rod
Morris, Paul I.
Date
June 2005
Genre du document
Research report
Domaine
Sustainable Construction
Auteur
Stirling, Rod
Morris, Paul I.
Date
June 2005
Genre du document
Research report
Description physique
8 p.
Secteur
Wood Products
Domaine
Sustainable Construction
Champ de recherche
Advanced Wood Materials
Sujet
Wood
Wood decay
Resistance
Research
Série
W-2168
Localisation
Vancouver, British Columbia
Langue
English
Résumé
Western redcedar (WRC) is renowned for its high durability, which is due at least in part to the presence of extractives that are toxic to decay fungi. Western redcedar's naturally low equilibrium moisture content (EMC) may also be a protective factor, since fungi typically require 30% moisture content to grow. Extractives are thought to contribute to the low EMC by blocking water adsorption sites on the wood. The present work compared the EMC of extracted and un-extracted WRC heartwood and sapwood. Extracted WRC heartwood had higher EMC than un-extracted WRC heartwood in samples not affected by fungi, and WRC sapwood had higher EMC than adjacent heartwood. The presence of extractives was identified as being associated with the low EMC of WRC heartwood in these samples.
Extractives - Research
Extractives - Decay resistance
Fungi - Natural resistance to
Fungi - Wood destroying - Research
Documents
Moins de détails

7 notices – page 1 of 1.