The scope of the information found in this publication will provide the reader with a comprehensive understanding of the silvics, characteristics, manufacturing and end-uses of major commercial softwoods in eastern Canada. While the section on silvics is intended to provide wood professionals with basic knowledge of each species, the other sections provide comprehensive information on various wood properties and characteristics, primary and secondary manufacturing opportunities and various end-use products.
It will provide the wood industry with a high-quality, species-specific reference tool that will enable it to manage, process and utilize each species efficiently and to add value along the forest-wood value chain from "seed-to-tree-to-product". Other groups will find it useful:
- Forest managers: comprehensive information on the effects of silvicultural practices on various wood characteristics and end-uses.
- Forest and wood professionals: reference tool to gain comprehensive knowledge of the species they work with on a daily basis.
- Governments: can use the information to define scientifically sound forest management policies and regulations.
- Public: heighten awareness of the economic value of this resource, its renewability and its contribution to economic sustainability.
Le présent rapport est une exploration conceptuelle des implications, répercussions et retombées globales résultant de la mise en place d'une usine intégrée pour la production de grands panneaux en bois massif de tailles standards devant servir comme matière première principale utilisée par une usine de meubles en bois massif hautement automatisée. Le document donne d’abord une vue d'ensemble du réseau actuel de création de valeur du mobilier en bois massif de la forêt au client. Il présente ensuite une évaluation globale des possibilités d'amélioration facilitant une agilité accrue des entreprises de même qu’un examen des technologies avancées qui pourraient être introduites dans les procédés cruciaux. Sont finalement discutés les gains attendus en agilité selon différentes hypothèses.
Ce travail se veut la suite d'un précédent travail portant sur un modèle de référence sur les capacités fondamentales d’agilité devant être présentes dans les principaux procédés utilisés par les entreprises de meubles. Un objectif corollaire de ces projets est de définir les propriétés clés d’agilité des technologies utilisées pour développer ces capacités. Sur la base de ce modèle de référence, on a dressé une typologie pour cadrer la taxonomie de l'interaction des stratégies de marché pour les produits de meubles et la compétitivité des priorités qui devraient être ciblées par des entreprises de meubles recherchant l’agilité. L'adéquation du modèle proposé pour établir la typologie a été étudiée selon des études de cas réalisées auprès de deux entreprises de fabrication de meubles. Pour plus de détails sur le modèle de référence et les études de cas, voir Azouzi et al., 2007a, 2007b, 2007c, 2009a, 2009b.
Cette étude a mesuré l’effet de l’entreposage des billes d’une durée de 20 mois sur la qualité de l’écorçage à anneau et sur la qualité du débitage par une équarrisseuse-déchiqueteuse à tête conique. L’écorçage a été réalisé en usine tandis que le débitage a été fait sur le banc d’essai d’équarrisseuse dans les laboratoires de FPInnovations à Québec. Les billes ont été écorcées et débitées à l’état frais et après des périodes de 5, 7 11, 15 et 20 mois d’entreposage. L’écorceuse à anneau est de marque Nicholson (A5, 17 po, 6 pastilles) et la vitesse d’alimentation utilisée de 69 m/min (225 pi/min). La tête de l’équarrisseuse (Ø 14 po, 6 couteaux) a une vitesse linéaire de couteau de 1220 m/min (4000 pi/min) et une vitesse de rotation de 1300 tr/min. La bouchée est de 22,2 mm (7/8 po). Les billes ont été écorcées et débitées à température ambiante ; les paramètres d’écorçage sont les mêmes que ceux utilisés lors de la production. 141 billes d’épinette noire (Picea mariana [Mill.] B.S.P.) de diamètre moyen de 14,7 cm au fin bout, de teneur en humidité (base anhydre) de 79,3 % et de densité basale de 393 kg/m3 ont été transformées. Les patrons de débitage (4x4, 4x5, 4x6 et 6x6) ont été utilisés afin d’obtenir le meilleur rendement matière de chaque bille.
Les plus grandes pertes de teneur en humidité sont survenues après 5 et 7 mois d’entreposage ; par la suite la teneur en humidité est demeurée semblable et au-dessus du point de saturation des fibres. La proportion de grandes particules de copeau (7/8 et 1 1/8 po) a augmenté après 5 et 7 mois d’entreposage, tandis que la proportion de particules plus fines (3/16 po et fines) a diminué.
La qualité d’écorçage est demeurée constante dans les 11 premiers mois d’entreposage ; la perte en volume de bille a oscillé entre 0,7 % et 1,1 %. Par la suite, les pertes en volume de billes ont augmenté à 2,3 et 2,7 % (à 15 et 20 mois). Ces pertes sont attribuables à la détérioration des billes par la coloration et la carie qui ont fait leur apparition après 15 et 20 mois d’entreposage. L’aubier était totalement affecté tandis que le duramen l’était sur une grande partie. De même, le lien entre le bois et l’écorce s’est grandement détérioré entre les mois 11 et 15. De grands lambeaux d’écorce tombaient lorsque les billes étaient manipulées ; l’absence d’écorce rendait l’aubier encore plus exposé à la pression des outils d’écorceuse, ce qui provoquait plus d’arrachement de bois.
La proportion des pièces classée Premium 1/32, 1/16 et 1/8 en ce qui a trait à l’arrachement maximal de bois est restée semblable tout au long de l’étude, et ce, malgré la détérioration des bois aux mois 15 et 20. Les pertes monétaires ont très peu progressé lors de 11 premiers mois d’entreposage, elles sont passées de 1,86 % à 2,2 %. Par la suite, les pertes monétaires sont passées de 2,8 % à 3,1 %, principalement à cause de la carie et de la coloration qui sont apparues après 11 mois d’entreposage et sans cette détérioration, la qualité de débitage serait restée similaire.
Dans les conditions de cette étude, on peut affirmer que la rentabilité commence à être affectée après 11 mois d’entreposage des billes.
The primary objective of this project was to assess the potential for Canadian sawmills to use simulation techniques and tools to optimize lumber yard management. More specifically, this study aims at assessing the potential benefits of improving the management of green lumber inventories, that is to say the wood supplies that circulate between the sawmill and the kilns. Sawmill managers can benefit from optimizing the location of lumber stockpiles by considering the next phase of the lumber manufacturing process (drying, planing or shipping) and the handling equipments’ parameters, such as load capacity, tasks and speed.
In the absence of off-the-shelf software to simulate sawmill lumber yards, we have developed a lumber yard operating model using a general purpose simulation software application adapted to the study sawmill situation.
We first simulated the typical lumber yard operation, and then used the model to assess the effects of modifying lumber yard design. We quantified the impact of changing the location of certain types of products to reduce the use of wheeled lumber handling equipment. By changing the location of only eight types of products a 10 % reduction in the distance travelled by one of the loaders used in the study resulted. This represents yearly savings of approximately $16,000 for the study sawmill. A thorough analysis of the location of each type of lumber stockpile shows a potential annual savings of up to $50,000. Furthermore, this level of performance can be achieved without any capital investment.
A series of experiments were conducted with Forintek’s MDF pilot plant to investigate the impact of various process parameters on MDF dryer stack emissions. Resin types, resin loading, wood furnish and scavenger levels were among the factors investigated in this study. Stack emissions were analyzed for particulate matters (PM), speciated volatile organic compounds (VOCs) and total volatile organic compounds (TVOC).
Two series of results were reported. During the first series of test runs, the isokinetic PM sampling was not obtained while with the second series, all test runs were conducted under isokinetic conditions, which make results more reliable. PM results from the second series of runs did not indicate a clear impact of the investigated refining conditions. However, all PM results were well below provincial guidelines for PM emission limits.
Other results clearly showed that increasing resin loading resulted in an increase of individual VOCs (IVOCs) and total VOC (TVOC). The replacement of UF resin by MUF resin contributed to a decrease of both IVOCs and TVOC. The addition of scavenger decreased stack emissions of both IVOCs and TVOC in agreement with what has been observed with the resulting MDF/HDF products suggesting that in order to reduce stack emissions one could reduce resin loading ratios or increase scavenger loading in the manufacturing process by keeping in mind to any modification of these processing factors will impact of products mechanical and physical properties and on the final production costs.
The two trials conducted at a mill member showed excellent results with deviations less than 20% between the duplicates for IVOCs and less than 2% for the TVOCs results. Because of confidentiality, the participating mill is not identified.
Development of fire retardant composite panels. Part I. Fire-performance requirements for composite wood products and standard fire tests for demonstrating compliance with those requirements - Literature review
Wood belongs to the natural bio-composites of plant origin containing cellulose, hemicelluloses, lignin and other compounds. When exposed to fire or any other high intensity heat sources, wood, being a natural polymer, is subject to thermal decomposition (pyrolysis) and combustion depending on the environmental conditions. Combustion accompanied by heat release and chemiluminescence occurs when wood is in direct contact with air and with a physical, chemical or microbiological stimulus associated with heat release. There are increasing concerns about the fire performance of engineered wood products (EWP). Eventually, these concerns may likely extend to wood composite products such as oriented strand board (OSB), particleboard (PB), medium density fiberboard (MDF), and high density fiberboard (HDF) panels. From environmental and safety points of view, wood composite panels, like structural wood products, should have certain fire retardant properties and it is believed this fire issue will get more attention in the near future through environmental regulation development and end-use customers’ requirements.
A Canadian Forest Service (CFS) project in the Composites Program, entitled “Development of Fire Retardant Composite Panels (Project No. 5764),” was initiated in 2007. The aim of the project is to develop fire retardant OSB panel and low-density fiberboard (FB) through modification of wood furnish and/or adhesives with fire retardants and nano materials, and panel surface coating with fire retardant coatings and paints for improving fire performance. As part of the project deliverables, this report presents a review of the current literature on identifying fire performance requirements in Canada and the United States for wood and wood-based building products, OSB, HB, FB, low-density FB panels suitable for use as interior ceiling finish, and other composite wood products used in construction of buildings, and the standard fire tests specified in Canada and the United States for demonstrating compliance with those requirements. The literature review was conducted by Mr. Leslie R. Richardson, retired senior research scientist and Group Leader of Building Systems – Fire Program of FPInnovations - Forintek Division. It is believed that this literature review will be invaluable as a guide for acquiring information on fire performance requirements and standard fire test methods for wood and composite wood products. The full literature review is available in Appendix I.
Dans l’industrie du sciage les systèmes de monitorage du procédé sont encore relativement peu nombreux, comparativement à d’autres industries où ces systèmes sont omniprésents et essentiels à la rentabilité. Nous avons eu l’idée d’adapter le simulateur de sciage Optitek pour qu’il puisse servir d’outil de monitorage et de contrôle du procédé. Le concept consiste à récupérer les profils de billes, via les scanneurs à l’entrée des lignes de sciage, pour simuler la production de la scierie et comparer ses performances réelles à celles prévus par simulation en temps réel.
Une entreprise, AbitibiBowater, s’est montrée intéressée et une usine a été ciblée pour la réalisation d’un projet pilote. Le développement et l’implantation du système de monitorage avec Optitek s’est déroulé sur deux ans. La première année a été consacrée principalement à la planification du projet, à l’adaptation du simulateur Optitek pour un fonctionnement en temps réel et à la création d’un portail Web nommé Optitek Évolution. Lors de la deuxième année, le système a été implanté en usine et mis en route. Parallèlement, la scierie a été entièrement modélisée avec Optitek et les résultats ont ensuite été validés par une série de tests en usine.
La validation avait pour but de représenter aussi fidèlement que possible le niveau de performance de la scierie afin de pouvoir y faire un monitorage efficace. Les tests en usine ont permis de vérifier la précision des scanneurs de billes, quantifier les erreurs de débitage et évaluer les performances réelles de la scierie. Des indicateurs clés comme le facteur de consommation (m³/Mpmp), le rendement économique ($/m³), ainsi que la distribution des sciages ont servi à valider le modèle. Un filtrage des profils de billes a été nécessaire pour minimiser l’impact des mouvements lors de l’alimentation dans les scanneurs.
Après la validation du système, le transfert technologique a été fait au personnel d’usine et le monitorage a débuté. Une période de référence a permis d’expérimenter le système pour déterminer la bonne fréquence de monitorage. Des contraintes ont toutefois été observées compte tenu du mode d’opération de la scierie. Des quantités importantes de bois sortent ou entrent régulièrement de l’usine, et viennent influencer de manière significative les indicateurs de performance d’une faction. Il devient alors impossible de générer des indicateurs fiables sur de plus courtes périodes (2 heures par exemple). Pour obtenir un monitorage intéressant, il faut minimalement calculer une moyenne mobile sur 8 heures à partir de données prélevées aux 2 heures.
Le fonctionnement en mode « batch » et la capacité d’accumulation avant éboutage sont d’autres facteurs qui limitent la période minimale de monitorage. Dans des conditions idéales, une scierie fonctionnant sans mouvement de bois vers l’extérieur et opérant en mode « Scan & set », serait en mesure de faire un monitorage précis par période de 2 heures ou moins.
Investigation of combination catalyst system for UF resin in particleboard and MDF manufacturing. Part I. Preliminary evaluation of eleven catalyst systems for curing rate, stability and free formaldehyde emission
Ammonium chloride has been commonly used as catalyst for urea-formaldehyde (UF) resin in particleboard manufacturing in North America. To explore a suitable catalyst system as a substitute for ammonium chloride, 11 single and combination catalyst systems were evaluated by measuring the curing rate of UF resin with a differential scanning calorimetry (DSC) analysis in terms of DSC peak temperature, stability at room and elevated temperatures in terms of pH value, and free formaldehyde emission of cured resin. The catalyst systems investigated in the study included (1) A-1 (ammonium chloride), (2) A-2 ammonium sulfate, (3) A-3 (ammonium persulfate), (4) B-1 (ammonium sulfate + ammonium persulfate), (5) B-2 (ammonium sulfate + aluminum chloride), (6) B-3 (ammonium persulfate + aluminum chloride), (7) B-4 (ammonium sulfate + phosphoric acid), (8) B-5 (ammonium chloride + phosphoric acid), (9) C-1 (ammonium sulfate + aluminum chloride + triethanolamine), (10) C-2 (ammonium sulfate + phosphoric acid + triethanolamine), and (11) C-3 (ammonium chloride + triethanolamine + phosphoric acid). Overall better performance was observed for catalyst systems C-2, C-1, B-3, B-2, and A-2. These five catalyst systems were performed similarly to or even better than control A-1, and may be potential catalysts for particleboard manufacturing.
Wood checking at log and lumber ends is one of the most common defect and often results in great loss of wood value. The common method to prevent wood checking is to apply a coating on log or lumber ends. However, the effectiveness of various coating products on different wood species is not clearly established, and the expected efficacy of the products to prevent checking is often not reached. This project was conducted to evaluate the effectiveness of various wood coatings against wood checking and to optimize application process on log and lumber ends, as well as components of hardwood species.
Logs, green lumber and dried components of sugar maple and yellow birch were used in this study. Five commercial coating products produced in Canada and the USA were evaluated, and two application methods were examined. The treatments were conducted on 120 fresh logs, 200 boards and 100 components per wood species in 2006 and 140 logs per species in 2007.
The results of the study showed that all coating products used in the tests were able to effectively reduce check development in logs, lumber and components. The best treatment reduced checking in lumber and components up to 100% and in logs up to 80% for a 8-week period. The effectiveness level of the products varied depending on wood species, type of wood products, treating time, application method, and storage conditions. None of the products was totally superior to others under any of the test conditions.
Ammonium chloride is one of the catalysts that have been commonly used to catalyze urea-formaldehyde (UF) resin curing in particleboard and medium density fiberboard (MDF) manufacturing in North America. There are some limitations with this catalyst. It is known that ammonium chloride reacts with the free formaldehyde in the resin to generate strong acid for accelerating the resin curing rate. Thus, the catalytic impact of this catalyst on resin curing depends on the amounts of free formaldehyde available in the resin. It has been reported that recycling particleboard made with UF resins catalyzed by ammonium chloride may create polychlorinated dioxine compounds, which are classified as toxic materials.
To explore a suitable catalyst system as a substitute for ammonium chloride, four one-component catalyst systems and three combination-catalyst systems were characterized by differential scanning calorimetry (DSC) analysis, in terms of the resin curing rate and activation energy as influenced by the resin solid content and catalyst content. These catalyst systems included (1) ammonium chloride, (2) ammonium persulfate, (3) aluminum chloride, (4) oxalic acid, (5) combination catalyst I (ammonium chloride + ammonium persulfate), (6) combination catalyst II (ammonium chloride + triethanolamine + phosphoric acid), and (7) combination catalyst III (ammonium chloride + triethanolamine + phosphoric acid + hexamethylenetetramine). The test results showed that combination catalysts II and III had great potential as substitutes for ammonium chloride for catalyzing UF resin (particularly with a low F/U molar ratio), in terms of stability (higher pH values of catalyst solutions than ammonium chloride solution at room temperature) and catalytic impact (comparable to ammonium chloride). Ammonium persulfate appeared to be a more powerful catalyst, while combination catalyst I (ammonium chloride/ammonium persulfate) seemed to be a slightly stronger catalyst as compared with ammonium chloride. However, the catalyst solutions of ammonium persulfate and combination catalyst I showed lower pH values than that of ammonium chloride, which may influence the stability of resin system in terms of pot life. Aluminum chloride and oxalic acid had much greater catalytic impacts on the resin curing than the other five catalysts. The resin started curing after mixing with either aluminum chloride or oxalic acid, which would lead to a significantly shortened resin pot life. Therefore, these two catalysts cannot be used directly as catalyst for UF resin curing.
Investigation of combination catalyst system for UF resin in particleboard and MDF manufacturing. Part III. FTIR and DMA analyses of UF and MUF resin curing behaviors in the presence of twenty-four catalysts
In North America, ammonium chloride is one of the catalysts commonly used to catalyze urea-formaldehyde (UF) and melamine-urea-formaldehyde (MUF) resin curing in particleboard and medium density fiberboard (MDF) manufacturing. However, there are some limitations with this catalyst. A major limitation is that its catalytic impact depends on the availability of free formaldehyde in the resin. This is because the interaction of the catalyst with formaldehyde generates a strong acid, which accelerates the resin curing rate. Another major limitation is the possibility of polychlorinated dioxine compounds being formed during the recycling of particleboard made with UF resins catalyzed by ammonium chloride, which are classified as toxic materials.
To explore a suitable catalyst system as a substitute for ammonium chloride, a total of 24 catalyst systems were prepared from 12 chemicals, including aluminum chloride, aluminum sulfate, ammonium chloride, ammonium hydroxide, ammonium nitrate, ammonium persulfate, ammonium sulfate, hexamethylenetetramine, phosphoric acid, triethanolamine, triethylamine and urea. The 24 catalyst systems included 4 systems with 1 component (D-1, D-2, D-3, D-4), 6 with 2 components (E-1, E-2, E-3, E-4, E-5, E-6), 9 with 3 components (F-2, F-3, F-4, F-5, F-6, F-7, F-8, F-9, F-10), 3 with 4 components (F-1, G-3, G-4), and 2 with 5 components (G-1, G-2).
All catalyst systems were characterized for pH at room temperature, gel time, pot life, free formaldehyde (FF) release of cured resin, hydrolysis resistance (HR), variation of functional groups (before and after hydrolysis) characterized by Fourier transform infrared (FTIR) spectroscopy and strength development measured by dynamic mechanical analysis (DMA). Five to six hours was considered a reasonable pot life for UF and MUF resins when making adjustments to catalyst performance. Ammonium chloride, coded D-1 in this study, was used as a reference to set the other criteria for evaluating catalyst performance.
In the presence of formaldehyde in catalyst solutions, potential catalysts include D-2, D-3, E-1, F-1, F-4, F-5, F-9, F-10, G-1, G-2, G-3 and G-4. These catalyst systems caused a significant decrease in pH values when heated up (100oC). This result indicated that the formaldehyde may have reacted or interacted with some components of the catalyst systems.
In terms of gel time and pot life, potential catalyst systems seemed to be D-2, D-3, D-4, E-1, E-4, E-5, F-4, F-5, F-9, F-10, G-1 and G-2 for a low F/U UF resin; and D-2, D-3, D-4, E-1, E-2, E-3, E-5, F-9, F-10, G-1 and G-3 for low F/(U+M) MUF resin. It was observed that the curing of MUF resin needed a more acidic catalyst system than the curing of UF resin did. Thus, ammonium persulfate would be a key component in the catalyst system for a low F/(U+M) MUF resin.
In terms of free formaldehyde release and hydrolysis resistance of cured resins, most of the catalyst systems (except D-2, D-4, E-6, F-1, F-2 and F-9) seemed to be suitable for UF resin, while D-3, D-4, E-5, F-1 and F-5 appeared to be the systems suitable for MUF resin.
In terms of the change in relative concentrations of functional groups and the stability of resin chemical structure after hydrolysis, potential catalyst systems include E-1, E-6, F-1, F-3, F-5, F-7, F-8, G-3 and G4 for UF resin, and D-3, D-4, E-5, E-6, F-1, F-2, F-4, F-7, G-2 and G-4 for MUF resin.
In terms of the maximum modulus, or strength property, of completely cured resins, potential catalyst systems seemed to be series D, E (except E-4 and E-5), F (except F-1 and F-4) and G for UF resin, and series D (except D-2 and D-3), F (except F-6 and F-9) and G for MUF resin.
With respect to the estimated costs of catalyst systems, some systems cost less than the control of ammonium chloride (D-2, E-2, F-4, F-5, F-6, F-7), some are comparable to the control (D-4, E-1, E-3, E-4, E-5, F-9, F-10) and some cost more than the control but with costs that are considered reasonable (F-1, F-2, G-1, G-2, G-3, G-4). Only the cost of four catalyst systems (D-3, E-6, F-3, F-8) was considered much higher than the control.
It seems unlikely to be able to base the selection of an optimal catalyst that would satisfy all criteria in catalyzing UF and MUF resins. Thus, it is recommended that selection of a suitable catalyst be made on the basis of resin type and the important requirements of resin characteristics and board performance, as well as actual board manufacturing conditions.
Investigation of combination catalyst system for UF resin in particleboard and MDF manufacturing. Part IV. Evaluation of combination catalyst system as curing agent for UF resin in MDF panel manufacturing
This study was conducted in three phases to characterize a number of selected and optimized catalyst systems for pH of catalyst solution, gel time and curing behavior of resin by a differential scanning calorimetry (DSC) analysis. These catalyst systems were also evaluated for bond quality by manufacturing medium density fiberboard (MDF) panels and testing the resulting panels for internal bond (IB) strength, modulus of rupture (MOR) and modulus of elasticity (MOE), 24-h thickness swelling (TS) and water absorption (WA), and free formaldehyde (FF) emission.
In Phase I, four catalyst systems were selected to manufacture MDF panels with urea-formaldehyde (UF) resin having F/U molar ratio of 1.08 based on the previous study on the characterization of 24 catalyst systems (Wang and Wan 2008), including D-1 (ammonium chloride), F-10 (7.5 wt% ammonium sulfate + 2.5 wt% ammonium persulfate + 2.0 wt% urea + 88 wt% water), G-2 (7.5 wt% ammonium sulfate + 1.0 wt% aluminum sulfate + 1.5 wt% triethanolamine + 2.0 wt% urea + 0.5 wt% phosphoric acid + 87.5 wt% water) and G-4 (7.5 wt% ammonium sulfate + 1.0 wt% phosphoric acid + 1.5 wt% triethanolamine + 2.0 wt% urea + 88 wt% water). The test results of the panels indicated that combination catalyst systems G-4 and F-10 showed potential as substitutes for control catalyst D-1 (ammonium chloride).
In Phase II, seven catalyst systems were selected and evaluated by manufacturing MDF panel with UF resin having F/U molar ratio of 1.08, including three control catalysts, D-1, F-10 and G-4. The three new catalysts were derived from formulations of F-10 and G-4 by introducing triethanolamine and phosphoric acid from G-4 into F-10 and adjusting their contents in the catalyst formulations, including B-1 (6.0 wt% ammonium sulfate + 2.0 wt% ammonium persulfate + 1.2 wt% triethanolamine + 0.8 wt% phosphoric acid + 2.0 wt% urea + 88 wt% water), B-2 (6.0 wt% ammonium sulfate + 1.0 wt% ammonium persulfate + 1.8 wt% triethanolamine + 1.2 wt% phosphoric acid + 2.0 wt% urea + 88 wt% water) and B-3 (6.0 wt% ammonium sulfate + 1.0 wt% ammonium persulfate + 1.5 wt% triethanolamine + 1.8 wt% phosphoric acid + 2.0 wt% urea + 87.7 wt% water). The new catalyst B-4 (7.5 wt% ammonium sulfate + 1.5 wt% triethanolamine + 1.0 wt% aminosulfonic acid + 2.0 wt% urea + 88 wt% water) was derived from the formulation of G-4 by substituting aminosulfonic acid for phosphoric acid. Based on the overall panel performance, the combination catalysts B-4 and B-1 seemed to be the most promising as substitutes for control catalyst D-1 (ammonium chloride).
In Phase III, the combination catalyst B-1 was selected to further evaluate its potential against the control catalyst D-1 by manufacturing MDF panels with five different formulations of UF and MUF resins in terms of F/U molar ratio (1.10, 10.8, 1.05) and melamine content (0.1%, 2.5%, 5%). These five resins included Resin A (F/U 1.10/0.1% melamine), Resin B (F/U 1.08/0.1% melamine), Resin C (F/U 1.05/0.1% melamine), Resin D (F/U 1.08/2.5% melamine), and Resin E (F/U 1.08/5% melamine). The test results indicated that all five resins cured faster with B-1 than with D-1 in terms of shortened gel time and lower activation energy. Resin B and Resin C catalyzed by B-1 produced the overall best quality panels than other resins catalyzed by B-1 and D-1, which implies that B-1 would be more powerful for catalyzing UF resin curing and producing better bond quality compared with D-1. The study also implies that catalyst type and catalyst content should be properly adjusted according to resin formulation (such as F/U molar ratio and melamine content) in combination with pressing conditions (such as press time and temperature) in order to achieve the maximum bond quality in panels.
Investigation of combination catalyst system for UF resin in particleboard and MDF manufacturing. Part V. Evaluation of combination catalyst system as curing agent for UF resin in PB panel manufacturing
To evaluate the catalytic influence of combination catalyst system on urea-formaldehyde (UF) resin curing rate and bonding quality, a number of catalyst systems were selected based on the previous test results of this project. These systems included D-1 (10.0 wt% ammonium chloride + 90.0 wt% water), F-10 (7.5 wt% ammonium sulfate + 2.5 wt% ammonium persulfate + 2.0 wt% urea + 88.0 wt% water), G-2 (7.5 wt% ammonium sulfate + 1.0 wt% aluminum sulfate + 1.5 wt% triethanolamine + 0.5 wt% phosphoric acid + 2.0 wt% urea + 87.5 wt% water), G-4 (7.5 wt% ammonium sulfate + 1.5 wt% triethanolamine + 1.0 wt% phosphoric acid + 2.0 wt% urea + 88.0 wt% water), B-1 (6.0 wt% ammonium sulfate + 2.0 wt% ammonium persulfate + 1.2 wt% triethanolamine + 0.8 wt% phosphoric acid + 2.0 wt% urea + 88.0 wt% water) and B-4 (7.5 wt% ammonium sulfate + 1.5 wt% triethanolamine + 1.0 wt% aminosulfonic acid + 2.0 wt% urea + 88.0 wt% water). These catalyst systems were first characterized for the curing behaviors of UF resin in the presence of the catalysts with differential scanning calorimetry (DSC) analysis and the chemical structures of the cured resin with CP/MAS 13C nuclear magnetic resonance (NMR) spectroscopy. The catalyst systems were then evaluated by manufacturing a series of particleboards. The resulting boards were tested for internal bond (IB) strength, modulus of rupture (MOR) and modulus of elasticity (MOE), 24-h thickness swelling (TS) and water absorption (WA), and free formaldehyde (FF) emission.
This study was conducted in two phases. In Phase I, six catalyst systems (D-1, F-10, G-2, G-4, B-1 and B-4) were selected to manufacture particleboard with 1.2% catalyst content and a 170-second press cycle. The test results indicated that combination catalyst G-4 resulted in stronger particleboard than the other catalysts in terms of IB, MOR and MOE properties; catalyst type seemed to have a little influence on board water resistance and free formaldehyde emission. In general, G-4 seemed to be more powerful in catalyzing UF resin curing and producing stronger particleboard than the conventional catalyst D-1 (ammonium chloride) and the other four combination catalysts.
In Phase II of this study, the combination catalyst G-4 was further evaluated by manufacturing particleboard against control catalyst D-1 with three press cycles (140, 155 and 170 seconds) and three levels of catalyst content (0.9%, 1.2%, and 1.5%). The analysis of variance (ANOVA) indicated that board manufacturing conditions had a significant influence on IB strength and free formaldehyde (FF) emission rather than on other board properties. G-4 resulted in better quality boards than D-1 in terms of consistently higher IB strength and lower FF emission under each board manufacturing condition. This study also showed that G-4 was more powerful in catalyzing UF resin curing than D-1; thus, using G-4 has great potential for cutting down press time and reducing catalyst content. The improved bond quality and durability of the UF resin catalyzed by G-4 is probably due to the improved chemical structure of the resin in terms of the greater degree of resin crosslinking.
Ce rapport d’étape présente les principaux résultats obtenus dans le cadre d’un projet réalisé en collaboration avec le Laboratoire des Technologies de l’Énergie de Hydro-Québec. Au cours de la première année de ce projet, les propriétés mécaniques et physiques du bois de tremble modifié thermiquement à trois niveaux de température ont été déterminées en respectant les classes de traitement établies par la Finnish ThermoWood Association. Des travaux ont aussi été réalisés en étroite collaboration avec l’industrie afin d’évaluer le potentiel d’utilisation d’essences variées de bois feuillus modifiés thermiquement pour des applications telles que des composants d’instruments de musique, lames de plancher, armoires de cuisine et autres produits d’apparence pour usage intérieur. Ces travaux se poursuivront au cours de la prochaine année. Des essais additionnels permettront aussi d’étudier davantage l’impact des programmes de traitement, plus précisément l’effet du délai à la température maximale sur la couleur et les propriétés du bois. Finalement, le LTE poursuivra ses études portant sur l’efficacité énergétique du procédé de modification thermique.
One can summarize the work conducted under the Kyoto protocol by extracting some paragraphs from the Montreal climate conference press release.
Under the Kyoto Protocol, which entered into force 16 February 2005, more than 30 industrialized countries are bound by specific and legally binding emission reduction targets. As a first step, these cover the period 2008-2012. The Kyoto Protocol is now fully operational. The adoption of the Marrakesh accords formally launches emissions trading and the other two mechanisms under the Kyoto Protocol. Carbon has now a market value. Under the clean development mechanism, investing in projects that provide sustainable development and reduce emissions makes sound business sense. The Joint Implementation (JI) adopted by the parties is one of the mechanisms which allow developed countries to invest in other developed countries and thereby earn carbon allowances which they can use to meet their emission reduction commitments. In addition to this, the clean development mechanism allows industrialized countries to invest in sustainable development projects in developing countries and thereby earn carbon allowances.
“With these decisions in place, we now have the infrastructure to move ahead with the implementation of the Kyoto protocol” said Richard Kinley, head of the United Nations Climate Change conference. It sets solid basis for future steps to bring emissions down he added.
All Kyoto Protocol Parties, including Canada, are now moving ahead to meet their GHG emission reduction commitments. In the past few years, Canada has developed and set strategies to meet our commitments. However, Canada has since changed for a new conservative government and a new strategy has been published first in April and the proposed greenhouse gas regulations are expected to be published in the Canada Gazette later this year, and the regulations finalized in 2009 to come into force as planned on January 1, 2010 according to the minister.
During this fiscal year two Canadian provinces took important steps in regards to climate change by adopting regulations to reduce their respective GHG emissions. The province of BC has published its own green house gas reduction targets through the Bill 44 in which the province has set reduction targets by 2020 for 33% and 80% by 2050 relative to 2007 emissions levels for both. In 2007 the Quebec government announced the first carbon tax in Canada to Oil companies to pay a new energy tax of 0.8 cents a litre for gasoline distributed in the province and 0.938 cents for diesel fuel. The province has also adopted California’s greenhouse gas standards for new light-duty vehicles.
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.
Experimental works were carried out to produce high density fibreboard (HDF) using wood furnish with different wood species and geometries that are particularly used in Eastern Canada. The furnish included mixed softwood sawdust, mixed hardwood sawdust, aspen chips and mixed hardwood chips. The fibre refining was carried out with MDF pilot plant at the steam pressure of 6, 7.5 and 9 bars with retention time of 2.5 minutes and refining speed of 2500 rpm. Ten different types of wood fibres under different refining process conditions were produced and a total of 36 HDF panels were made.
Based on the results of this study, the following conclusions are made:
Under the same refining and hot pressing process conditions, different mechanical and physical properties of HDF panels were obtained with different raw materials. However, the properties of the panels were not consistently in favour of one particular type of the raw material.
With the same raw materials (60% softwood sawdust and 40% hardwood sawdust), the refining steam pressure had a strong impact on the panel properties. The properties studied were generally improved when the steam pressure was reduced from 9 bar down to 6 bar. This obvious difference in panel properties when using different refining steam pressures suggests that the required process conditions can be quite different for different raw materials and optimisation of the refining parameters are required for different types of raw materials.
There were no obvious differences in panel properties when using different sizes of raw materials with the same hardwood and softwood mixing ratio.
No obvious improvement in panel properties was observed with chemically pre-treated wood furnish under the process conditions used. However, speculation can be made that the UF resin was quite advanced and a higher degree of resin pre-cure occurred when using blowline resin blending and hot air drying with chemically pre-treated materials. That could be the major reason why we could not observe the improvement of the panel properties when using the pre-treatment or substantial reduction of IB and other properties when reducing hot pressing time.