In recent years in North America, studs made from short lengths of lumber connected by finger-jointing have gained popularity due to their improved straightness when compared to solid wood studs. To gauge performance when exposed in exterior applications, Forintek installed an above-ground field test of CCA-treated and untreated 2x4 spruce-pine-fir finger-jointed studs in 1980. After eighteen years of exposure, the CCA-treated material was free from decay, compared to moderate decay present in untreated samples.
L'innovation technologique a sans nul doute été l'élément moteur dans la croissance remarquable qu'a connu l'industrie canadienne du panneau de bois au cours des 50 dernières années. Le défi consiste maintenant à définir la direction qu'elle doit prendre pour respecter l'évolution du marché et de la consommation. La carte routière se veut un guide qui aidera l'industrie à relever ce défi en identifiant les techniques nouvelles et prometteuses et en suggérant certaines priorités pour l'avenir. Aussi cette publication propose des recommandations quant à l'infrastructure et à l'encadrement qui pourraient aider les divers secteurs de l'industrie à accélérer pour s'engager sur la voie rapide de l'innovation. La carte routière technologique porte sur les types de panneaux suivants: contreplaqués de résineux, panneaux de lamelles orientées (OSB), panneaux de particules et panneaux de fibres de moyenne densité (MDF). Les contreplaqués de feuillus sont couverts en moindre détail. Aussi quelques mentions sont faites sur les matériaux hybrides qui combinent plusieurs types de panneaux ou des composantes nouvelles.
This guide is a companion to the "High speed planer adjustment Manual" published by Forintek Canada Corp. Precision tools have been developed to control and to properly adjust all critical parts in planers. Methods to measure depth of cut and to align planer guides and ancillary equipment are suggested. Practical indications are also given for level and parallelism. Finally, the guide provides information on knife grinding, causes of surface defects and maintenance tips. Operators, mechanics, quality controllers, engineers and plant managers can all benefit from this practical Manual.
Ce guide se présente comme le complément du "Manuel d'ajustement des raboteuses à haute vitesse" publié par Forintek Canada Corp. Des outils de précision ont été développés afin d'effectuer la vérification et la mise au point de raboteuses. Des méthodes sont proposées pour contrôler les profondeurs de coupe et positionner correctement tous les éléments d'une raboteuse. A ceci s'ajoutent des conseils de nivellement, de parallélisme et d'alignement des guides de raboteuses et des équipements auxiliaires. L'affûtage des couteaux, l'identification des défauts de surface et l'entretien de la machinerie viennent compléter le guide. Les opérateurs, les mécaniciens ainsi que les ingénieurs et les directeurs d'usines y trouveront des renseignements pratiques.
Technological innovation has proven to be the prime vehicule for the remarkable development of the wood composite panel industry in Canada over the last half century. The challenge for the future is to maintain the place and to make appropriate choices in setting the direction of technological innovation. The Roadmap is intended to help the industry meet this challenge by establishing the importance of innovation to the major sectors in the panel industry and identifies new and promising technologies along with suggested priorities for the future. This document also lays out recommendations related to infrastructure and organization that may help the various sectors of the industry shift into high gear and assume a leadership role. The panel types included are: softwood plywood, oriented strandboard (OSB), particleboard and medium density fibreboard (MDF). Hardwood plywood is covered in less detail. Hybrid products which combine two or more panels, or panels with other materials, into a single product are also mentioned.
Adhesion and Adhesives - Composite Materials
Building materials - Composites - Research
Oriented Strand Board (OSB)
Medium Density Fibreboard (MDF)
Part of a technology roadmap series from Industry Canada: http://www.ic.gc.ca/eic/site/trm-crt.nsf/eng/rm00094.html
Basedon a preliminay testing, an optimized procedure for in-panel variability evaluation has been developed. A database was created consisting in fifty-five 0-2 OSB panels from nine member mills of the SBA conforming to the Canadian standards. The panels have been evaluated at the Eastern Laboratory of Forintek Canada Corp. and at the Alberta Research Council. Each panel was spit into 18 squares containing specimens for conducting tests on tensible strength perpendicular to surface (IB), thickness swelling (TS), water aborption (WA), moisture content (MC), density, thickness and static bending (MOR/MOE). Variance was used as the criteria for in -panel variability.
A survey with experts from the industry and research centres estimated that the variability on thickness, MOR/MOE parallel to forming, TS and IB is the most critical for the applications of OSB. According to the tests results, the most variable properties were MOE (variance from 405 to 676 GPa), MOR (variances from 28 to 38 MPa) parallel to forming and IB (variances from 5 to 11 kPa). The in-panel variability was on average ten times higher compared to among-panel variability, and the in product vatiability was three times as high as the among product variability. Density variation significantly affected only the variations in MC, WA, MOR and MOE. Density at break point and panel core density did not show better correlation correspondingly with MOR and MOE compared to average density. Further research is suggested to grade the factors of variability in OSB panels by their importance, to determine the criteria for acceptable limits of property variations and to define methods for on-line monitoring of horizontal density distribution.
Cette étude permet d’identifier des problèmes d’écorçage dans six scieries, de l’Abitibi et du Lac St-Jean, transformant de l’épinette noire. Dix-sept écorceuses Cambio (18, 24 et 30 po) et sept écorceuses Nicholson (12 et 17 po) ont été étudiées en hiver et en été. Les pertes en volume de sciage sont de 8% en hiver et de 3,5% en été. Les pertes en volume de billes sont de 11% en hiver comparativement à 5,3% en été. La quantité de fibre de bois dans l’écorce est de 24,2% en hiver chutant à 9,5% en été. La superficie d’écorce restante sur les billes après écorçage est de 7,2% en hiver et de 4,2% en été. Le taux d’écorce dans les copeaux passe de 1,9% en hiver à 0,6% en été. De grandes lacunes en matière de maintenance sont constatées (forces inégales des outils, bandes élastiques endommagées, pastilles usées, etc.). De grandes différences de design des écorceuses sont notées (angles d’attaque, force des outils, géométrie de la pastille, géométrie des outils, etc.) Aussi, des problèmes d’opération des écorceuses sont observés (plus d’une bille alimentée au même moment, anneau bourré d’écorces, etc.). Aucune usine ne se démarque des autres par sa qualité d’écorçage et chaque usine opère avec des paramètres d’écorçage complètement différents des scieries ayant les mêmes équipements et pratiquement la même ressource. Aucune marque d’écorceuse n’obtient des performances supérieures à d’autres. Suite à notre étude, une usine, possédant des Cambio a décidé de réaligner et de réajuster ses équipements, a fait chuté la quantité de fibre arrachée et la quantité d’écorce restante de ses billes. Cette usine obtient de loin le meilleur écorçage observé en industrie. Les équipements existants sont donc capables de faire un excellent écorçage s’ils sont bien ajustés et entretenus (les limites de l’équipement doivent être cependant respectées).
Up to twenty-three OSB products from Canada and US were tested for their VOCs. The results collected indicated that OSB panels emit at a very low level, in the order of few parts per billion (ppbs). The emission of monoterpenes such as alpha and beta-pinenes, camphene, carene and limonene from all of the tested OSB panels were very minor when they were present. In order to put in perspective the OSB panels emissions, a few tests were conducted on panels bonded with urea-formaldehyde resin and MDI. Results indicated that more VOCs and formaldehyde emit from the UF bonded panels compared to the PF or MDI bonded OSB panels. The UF emitted formaldehyde remains however far less than the 0.3 ppm recommended formaldehyde emission level by the new Composite Panel Association (CPA). VOCs observed from UF bonded panels consist mainly of monoterpenes which are naturally emitted from the softwood furnish used for the particleboard manufacturing and of formaldehyde at a level.
The evaluation of the long term effect on OSB panel emissions showed that all emitted individual chemicals (IVOC) and total emitted volatile organic chemicals (TVOC) decreased with exposure time. However, the two-week long term exposure period was not long enough in most cases to reach a 0 percent emission level. The positive aspect of these results is related to the fact that during the two to three-week delivery period to the client, the emissions are reduced by up to 90% of their initial first day value.
During the investigation of the effect of some key processing parameters on the final product emission characteristics, the drying temperature of the furnish and its moisture content as well as the pressing time and temperature and the resin contents were evaluated. Three OSB mills supplied the furnish (green and dried wafers) and the panel products. Results indicated that emissions from the wafers decrease in most cases when dried at high temperatures compared to the air-dried wafers for a given moisture content. Because the furnish composition (percentage of softwood compared to hardwood) can be different from one mill to another, one can anticipate a certain impact on the furnish emission characteristics and thus on the OSB products emissions. However, after a few days of exposure, the three OSB panels showed almost the same emission level.
The investigated furnish drying conditions showed very clearly that the drying temperature plays an important role on its emissions. Results indicated a gradual reduction of the TVOC, the emitted aldehydes and ketones when a furnish, dried at different temperatures, i.e., from ambient to high temperatures, is exposed in the environmental chamber. Also, the combined effect of moisture content and drying temperatures on furnish emissions showed, as expected, an increase of the detected TVOC as the moisture content and the drying temperature increase. This result support the fact that air-dried furnish should emit more than a furnish dried at high temperature when exposed in the environmental chamber conditions. However, at very high drying temperature, the furnish starts to degrade and an increase of the emission level could be observed.
Results acquired to date indicated that resin contents, pressing times and temperature values selected for the 27 different OSB panel processing conditions, were not different enough to have a significant impact on the composite panels emission levels. The total emitted chemicals (TVOC.) from the 27 OSB panels compare very well to the 23 industrial TVOC values. This result indicates that it should be necessary to find other combination values for the resin contents, the pressing times and the temperatures, quite different from their corresponding industrial values to better evaluate their impact on the resulting panel VOC emission patterns, and this should be done without affecting the product quality. The acquisition of such data will certainly have less interest for the wood composite panel industry if the manufacturing cost has changed but it will help for a better understanding of these parameters impact on the product emission characteristics.
One of the objectives of this project was to develop a quality control monitoring guideline. The twenty-three (23) North American OSB products tested in this project showed that the maximum TVOC observed was less than 0.04 parts per million (ppm), and the maximum detected formaldehyde less than 0.014 parts per million (ppm), which represents one twentieth of the 0.3 ppm of formaldehyde recommended value by the CPA for the particleboard and medium density fiberboard (MDF) products. Based on these results, we have recommended a voluntary, twice per year, VOC emission quality control for each OSB product to the OSB industry. A detailed procedure for sample collection, preparation and shipping to the Forintek Laboratory at Ste-Foy is described. The sample conditioning, emission collection and characterization procedures will be the same as those described in this report.
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.
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.
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.