Azmul Huda, Pierre Périnet, Yves Fortin, Roger E. Hernandez, Ahmed Koubaa, Alain Cloutier. Phenotypic and genotypic correlations for wood properties of hybrid poplar clones of Southern Quebec. 2018. Forests 9(3):140
DOI : 10.3390/f9030140
This study aims to understand the phenotypic and genotypic correlations among wood anatomical, physical, and mechanical properties of hybrid poplar clones. Samples were taken from seven clones grown on three sites in Southern Quebec, Canada. Five trees per clone were randomly sampled from each site to measure anatomical (fiber length, fiber proportion, vessel proportion, fiber wall thickness, tension wood), physical (basic density, volumetric, longitudinal, tangential, and radial shrinkage), and mechanical wood properties (flexural modulus of elasticity (MOE), modulus of rupture (MOR), ultimate crushing strength parallel to the grain). The observed phenotypic and genotypic correlations between these wood properties were moderate to strong, except for fiber length and vessel proportion. Genotypic correlations for all wood properties were higher than for corresponding phenotypic correlations. Furthermore, fiber length showed weak correlations, whereas, vessel proportion showed strongly negative correlations with all other properties. Strong correlations were also found among fiber proportion, fiber wall thickness, basic density, and mechanical properties. Furthermore, results from this study show close genotypic and phenotypic correlations between fiber proportion, fiber wall thickness, and wood density, which consequently affect the mechanical performance of wood products. These findings indicate that there is a substantial opportunity to improve wood quality by selecting several wood properties for different end uses. © 2018 by the authors.
Cyriac-Serge Mvolo, Jean Beaulieu, Marc Mazerolle, Alain Cloutier, Ahmed Koubaa. Variation in wood quality in white spruce (Picea glauca (Moench) Voss). Part I. defining the juvenile-mature wood transition based on tracheid length. 2015. Forests 6(1):183-202
DOI : 10.3390/f6010183
Estimations of transition age (TA) and juvenile wood proportion (JWP) are important for wood industries due to their impact on end-product quality. However, the relationships between analytical determination of TA based on tracheid length (TL) and recognized thresholds for adequate end products have not yet been established. In this study, we used three different statistical models to estimate TA in white spruce (Picea glauca (Moench) Voss) based on TL radial variation. We compared the results with technological maturity. A two-millimeter threshold, previously suggested for good paper tear strength, was used. Tracheid length increased from pith to bark and from breast height to upper height. Juvenile wood (JW) was conical with the three models. At breast height, TA ranged from 11 to 27 years and JWP ranged from 15.3% to 47.5% across the three models. The linear mixed model produced more conservative estimates than the maximum-quadratic-linear (M_Q_L) model. Both the linear mixed model and the M_Q_L model produced more conservative TA estimates than the piecewise model. TA estimates by the MIXED model, and to a lesser extent by the M_Q_L model, were equivalent to those for real mature wood, whereas TA estimates by the piecewise model were considerably lower, falling into the transition wood area.
Azmul Huda, Yves Fortin, Roger E. Hernandez, Alain Cloutier, Ahmed Koubaa. Variation of the physical and mechanical properties of hybrid poplar clones. 2014. BioResources 9(1):1456-1471
Patrice Soulonganga, Martin Claude Ngueho Yemele, Michael P. Wolcott, Tatjana Stevanovic, Alain Cloutier, Ahmed Koubaa. Effects of hot water treatment of raw bark, coupling agent, and lubricants on properties of bark/HDPE composites. 2013. Industrial Crops and Products 42(1):50-56
DOI : 10.1016/j.indcrop.2012.05.012
Hot water treated and untreated black spruce bark (BSB) and trembling aspen bark (TAB) fibers were combined with high density polyethylene (HDPE) to produce bark thermoplastic composites by extrusion. Bark fibers of three size categories (fine, medium, and coarse) were used at contents of 50% and 60% based on oven dry weight. The effects of hot water treatment of raw bark and the addition of coupling agent (MAPE) and lubricants (OP-100, talc) on the flexural and tensile properties of bark/HDPE composites were investigated. Results showed a significant impact of hot water treatment on tensile properties of composites made with BSB and on tensile and flexural strength of composites made with TAB. The addition of coupling agent and lubricants significantly improved the flexural and tensile strength properties of bark/HDPE composites but reduced toughness and strain.
Hassine Bouafif, Patrick Perré, Alain Cloutier, Ahmed Koubaa. Creep behaviour of HDPE/wood particle composites. 2013. International Journal of Microstructure and Materials Properties 8(3):225-238
DOI : 10.1504/IJMMP.2013.055385
The effect of particle type, size, content and manufacturing process on the creep behaviour of wood particles/High Density Polyethylene (HDPE) composites has been investigated. Short-term creep tests at different temperatures were carried out and modelled using the Bürger's model and the Findley power law. The creep of the composites was found to increase with temperature due to the mobility of the amorphous bulk and tie HDPE molecules. Increased wood particle content generally decreased the creep level. Jack pine composites exhibited the highest creep reduction due to the chemical composition of the fibres surface and the efficiency of adhesion mechanism between fibres and the HDPE. Injection and compression processes led to better creep behaviour than the extrusion process due to differences in the composites microstructures. Particle size did not show important impacts on the creep properties. Findley power law led to better prediction of long time creep behaviour of the composites.
Azmul Huda, Roger E. Hernandez, Alain Cloutier, Ahmed Koubaa. Anatomical properties of selected hybrid poplar clones grown in southern Quebec. 2012. BioResources 7(3):3779-3799
The anatomical properties of seven hybrid poplar clones grown in three sites in southern Quebec, Canada were investigated. Radial and longitudinal variations in selected anatomical properties of wood were measured by image analysis of transverse sections and by fiber quality analysis. Results indicate that all measured anatomical properties varied significantly across sites. Clonal variation was highly significant for all anatomical properties studied, and broad-sense heritability ranged from 0.10 (average vessel lumen area) to 0.76 (cell wall area percentage). Genetic gain was positive for all anatomical properties. The variation in radial pattern was characterized by a rapid increase in the first few years in fiber length, width, and proportion, wall thickness, and percent cell wall area. Ray proportion remained constant, whereas the vessel lumen area and proportion decreased with cambial age.
Alain Cloutier, Changhua Fang, Pierre Blanchet, Ahmed Koubaa. Densification of wood veneers combined with oil-heat treatment. part 2: hygroscopicity and mechanical properties. 2012. BioResources 7(1):925-935
In an effort to achieve high mechanical performance and improved dimensional stability, densification combined with oil-heat treatment (OHT) was performed. In our previous study, OHT was successfully applied to densified veneer, which resulted in improved dimensional stability. In the present study, the impact of OHT on densified wood veneer hygroscopicity and mechanical properties was determined. OHT at 180, 200, and 220ºC for 1, 2, and 3 hours was applied to densified Aspen (Populus tremuloides) veneers. OHT was found to be an efficient treatment to reduce the hygroscopicity of densified aspen veneers, although OHT had a negative impact on Brinell hardness. However, due to the contribution of densification, the hardness of oil-heat treated veneers was still two to three times higher than that of non-densified veneers. Similar results were found for tensile strength. Bending strength increased slightly at low OHT temperature, and then decreased at high temperature. Bending strength of oil-heat treated densified veneer samples was higher than that of non-densified ones. No significant effect of OHT was found on tensile MOE, but bending MOE increased after OHT. Compared to OHT duration, OHT temperature had a larger impact on densified wood hygroscopicity and mechanical properties.
Changhua Fang, Nicolas Mariotti, Alain Cloutier, Pierre Blanchet, Ahmed Koubaa. Densification of wood veneers by compression combined with heat and steam. 2011. European Journal of Wood and Wood Products 70(1-3):155-163
DOI : 10.1007/s00107-011-0524-4
Wood veneer 700×700 mm2 specimens made with aspen (Populus tremuloides) and hybrid poplar clone 15303 (Populus maximowiczii × Populus balsamifera) were densified using heat, steam, and pressure. Temperatures of 140, 160, 180, 200, and 220°C were applied at a maximum steam pressure of 550 kPa and maximum press hydraulic pressure ranging from 4.5 to 9.0 MPa. After densification, the oven-dry density increased significantly, veneers darkened, and lathe checks that were present on veneers before densification were conglutinated and veneer surface roughness decreased. Densified veneers showed markedly reduced hygroscopicity: the higher the densification temperature, the lower the wood hygroscopicity. The Brinell hardness of densified veneer was about two to three times that of control for both aspen and hybrid poplar. Tensile and bending strength also increased significantly after densification. However, the mechanical properties of densified veneers decreased slightly with increased densification temperature. The modulus of elasticity in tension and bending increased after densification, especially at high temperatures. A very high compression set recovery was found for veneers densified at low temperatures. Recovery decreased dramatically when densification temperature exceeded 180°C. Almost no recovery was found for veneers densified at 220°C.
Papa Niokhor Dioufa, Tatjana Stevanovic, Changhua Fang, Alain Cloutier, Pierre Blanchet, Ahmed Koubaa, Nicolas Mariotti. Effects of thermo-hygro-mechanical densification on the surface characteristics of trembling aspen and hybrid poplar wood veneers. 2011. Applied Surface Science 257:3558-3564
DOI : 10.1016/j.apsusc.2010.11.074
The effect of thermo-hygro-mechanical (THM) densification temperature on the surface color, roughness, wettability, and chemical composition of tremblingaspen (Populus tremuloides) and hybridpoplar (Populus maximowiczii × P. balsamifera) veneers was investigated. Veneers were subjected to four THM densification temperatures (160 °C, 180 °C, 200 °C, and 220 °C). Veneer color darkened with increasing THM densification temperature. Surface roughness decreased between 160 °C and 200 °C. Wettability decreased after THM densification, but no significant difference was found between treated specimens. ATR-FTIR and XPS results confirmed that THM densification caused major chemical changes in veneer surfaces, and more pronounced at temperatures higher than 160 °C.
Patrice Soulonganga, Martin Claude Ngueho Yemele, Alain Cloutier, Michael P. Wolcott, Ahmed Koubaa. Effect of bark fiber content and size on the mechanical properties of bark/HDPE composites. 2010. Composites Part A 41:131–137
DOI : 10.1016/j.compositesa.2009.06.005
Black spruce and trembling aspen bark fibers and high density polyethylene were used to process bark– plastic composites by extrusion. Fibers of fine, medium, and coarse size and contents of 50% and 60% based on oven-dry weight were used. The effects of species, fiber content and size on the flexural and tensile properties of the composite were investigated and were found to be highly significant. Black spruce bark composites exhibited higher strength but showed more brittle behavior than aspen bark composites. The effect of content on mechanical properties was more important than size. Compared to wood flour composites, those from bark showed lower strength.
Hassine Bouafif, Patrick Perré, Alain Cloutier, Ahmed Koubaa. Effects of composite processing methods on wood particle development and length distribution: consequences on mechanical properties of wood–thermoplastic composites. 2010. Wood and Fiber Science 42(1):62-70
The relationship between structure and properties of high-density polyethylene (HDPE) filled with wood particles and processing techniques—injection molding, compression molding, and extrusion— was investigated. Wood particles were hammer-milled, sieved, and compounded into pellets at 35% by weight with HDPE using a twin-screw extruder. Coupling agent (ethylene-maleic anhydride copolymer) was added at 2% by wood filler weight. The pellets were used to produce test samples using the three processing techniques. The sensitivity of jack pine and several other wood particles (eastern white cedar, black spruce, and jack pine bark) to composite processing was analyzed. Bark particles showed higher propensity to generate fines than wood particles, possibly because of a higher thermal sensitivity. The major reduction in mean particle length was found to occur in the compounding process. Extrusion and injection molding contributed to particle length reduction to a lesser extent. Conversely, compression molding did not cause significant damage to wood particles. Stiffness and strength increased linearly with weight-averaged length.
Alain Cloutier, Martin Claude Ngueho Yemele, Papa Niokhor Dioufa, Pierre Blanchet, Tatjana Stevanovic, Ahmed Koubaa. Physical and mechanical properties of particleboard made from extracted black spruce and trembling aspen bark. 2008. Forest Prod. J. 58(10):38-46.
Bark residues are mostly used for thermal energy production. However, a better utilization of that resource could be as raw material for particleboard (PB) manufacturing. Bark is also a source of numerous extractives used in several fields including pharmacology and adhesive production. This study aims at analyzing the effect of hot water extracted bark particle content and size on the physical and mechanical properties of bark PBs including the modulus of elasticity (MOE), modulus of rupture (MOR), internal bond (IB), Janka hardness (HJ), thickness swelling (TS) and linear expansion (LE). Moreover, these properties were compared both to a control (100% wood particles) and to PB made from the same content of unextracted bark. The results showed that, while the mechanical properties of the PB made from extracted black spruce and trembling aspen bark decreased with increasing bark content, LE increased. PB made of fine particles often showed higher IB and lower TS values. Hot water extraction of the bark had a detrimental effect on all the physical and mechanical properties of the PBs produced except for the Janka hardness, where no significant decrease was found. TheMOEandMORof the PBs made from 50 percent black spruce and trembling aspen bark met the requirements of the ANSI standard for commercial (M–1) and underlayment (PBU) grades. In contrast, the dimensional properties (TS and LE) of all the boards did not fulfill the minimum requirements of the ANSI standard.
Hassine Bouafif, Patrick Perré, Ahmed Koubaa, Bernard Riedl, Alain Cloutier. Analysis of Among-Species Variability in Wood Fiber Surface Using DRIFTS
and XPS: Effects on Esterification Efficiency. 2008. Journal of Wood Chemistry and Technology. 28: 296–315.
DOI : 10.1080/02773810802485139
Variability in the chemical composition of surface properties of various wood
fibers (eastern white cedar, jack pine, black spruce, and bark) was investigated using
diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and X-ray photoelectron
spectroscopy (XPS). Both DRIFTS and XPS showed high variability in fiber
surface composition between species and between fiber types (sapwood, heartwood,
and bark). Fiber surface was modified by esterification reaction using a maleic anhydride
polyethylene (MAPE) treatment. DRIFTS failed to assess surface modification,
whereas XPS results showed that MAPE treatment increased the surface hydrocarbon
concentration of jack pine wood fiber, indicated by a decrease in oxygen–carbon ratio
and an increase in relative intensity of the C1 component in the C1s signal. Lignin
concentration variability on the fiber surface was determined as the major factor that
prevents esterification from taking place.
Martin Claude Ngueho Yemele, Pierre Blanchet, Alain Cloutier, Ahmed Koubaa. Effects of bark content and particle geometry on the physical and mechanical
properties of particleboard made from black spruce and trembling aspen bark. 2008. Forest Prod. J. 58(11):48–56.
Bark residues are mostly used for thermal energy production. However, a better utilization of that resource could be as raw
material for particleboard manufacturing. The use of bark in wood particleboard manufacturing is currently viewed negatively
due to the fact that an excessive bark content in the furnish produces significant adverse effects on strength properties and
dimensional stability of the boards. Strategies could be found to improve some properties of particleboard made from bark. The
effects of bark particle content and geometry on the physical and mechanical properties of the panels including the modulus of
elasticity (MOE), modulus of rupture (MOR), internal bond (IB), Janka hardness (HJ), thickness swelling (TS), and linear
expansion (LE) were investigated. The best panels in terms of properties were compared to a control made of 100 percent wood
particles. The results showed that, while the mechanical properties of the particleboard made from black spruce and trembling
aspen bark decreased with increasing bark content, LE increased and TS increased slightly. The IB of particleboard made from
50 percent bark content decreased with increasing particle size. Particleboard made from 50 percent black spruce bark showed
the highest MOE, MOR, and IB and the lowest LE with values 12, 37, and 54 percent lower and 45 percent higher than the
control, respectively. The MOE, MOR, IB, and HJ of boards made from 50 percent black spruce and trembling aspen bark met
the requirements of the ANSI A208.1 to 1999 standard. Particleboard made from trembling aspen bark showed the lowest TS.
Martin Claude Ngueho Yemele, Ahmed Koubaa, Papa Niokhor Dioufa, Pierre Blanchet, Tatjana Stevanovic, Alain Cloutier. Effects of hot water treatment of black spruce and trembling aspen bark raw material on the physical and mechanical properties of bark particleboard. 2008. Wood and Fiber Science 40(3):339-351.
The understanding of the interaction between bark extractives and adhesives is fundamental
in the manufacture of bark particleboard for optimum adhesive curing, and mechanical and physical
properties of the boards. The effect of hot-water treatment on black spruce and trembling aspen bark was
investigated to highlight its impact on the bark particles/phenol-formaldehyde adhesive system, and on the
physical and mechanical properties of bark particleboard made from hot-water-treated bark of both
species. Bark was soaked in hot water maintained at 100°C for 3 h. The results showed that the hot-water
treatment affects the physical and chemical properties of the bark by decreasing hydrophilic characteristics,
acidity, and the amount of condensable polyphenols that can react with formaldehyde. The mechanical
properties, including static bending and internal bond of particleboard made from untreated black
spruce and trembling aspen bark, were higher than those of boards made from hot-water-treated bark of
the same species. The thickness swelling of particleboard made from hot-water-treated black spruce and
trembling aspen bark was higher than that made from untreated bark. One exception occurred for particleboard
made from 100% trembling aspen bark for which no significant difference was found between
particleboards made from treated and untreated barks.
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Cyriac-Serge Mvolo, Ahmed Koubaa, Alain Cloutier, Jean Beaulieu. Modélisation de la proportion du bois juvénile chez l’épinette noire, l’épinette blanche et le pin gris 12e colloque de la Chaire AFD. Université du Québec en Abitibi-Témiscamingue, Rouyn-Noranda, Québec. (2010-11-13)
Émilie Robert, Suzanne Brais, Osvaldo Valeria, Alain Cloutier. Écosystèmes forestiers des complexes fluvio-glaciaires abitibiens :
Caractéristiques hydrauliques des sols et productivité forestière.
Fertilisation avec des cendres industrielles en milieu forestier 12e colloque de la Chaire AFD. Université du Québec en Abitibi-Témiscamingue, Rouyn-Noranda, Québec. (2010-11-13)
