Your search resulted in 306 documents. Displaying 25 entries per page.
Effect of growth rate and radial position on the natural durability of Douglas-fir
2012 - IRG/WP 12-10791
In terms of natural durability, Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) fame owns to the favourable characteristics of centuries-old trees harvested in old-growth North American forests. The properties of wood coming from plantations harvested between 50 and 100 years-old are likely to be different. In such stands, plantation density and thinning intensity may have a large impact on the...
C Pollet, J-M Henin, B Jourez, J Hébert
Development of a quality control assessment method to predict properties of heat treated wood
2012 - IRG/WP 12-40611
Heat treatment has been used to improve properties of non durable European species. Chemical modification of some of the wood components provides improved dimensional stability and biological performance against decay fungi while mechanical properties such as modulus of rupture are reduced. Quality control of commercially made thermally treated wood is one of the major challenges to allow its indu...
M Chaouch, K Candelier, S Dumarcay, A Pétrissans, M Pétrissans, P Gérardin
Differences between heat treated Pinus pinaster heartwood and sapwood
2012 - IRG/WP 12-40617
Heat treatment is a well known process to improve the durability and dimensional stability of less noble woods. The treatment can be applied for heartwood unlike the traditional treatments based on impregnation due to the difficulty of impregnating heartwood.
Pure sapwood and pure heartwood samples were treated in an oven at 190ºC and 200ºC for 2h, 4h and 6h. Dimensional stability, measured a...
B Esteves, L Nunes, I Domingos, H Pereira
Statistical analysis of durability tests - Part 2: Principles of time-to-failure and application on field test data
2013 - IRG/WP 13-20512
Service life prediction is an important topic in wood research, especially with regard to the Construction Products Regulation (CPR). Both laboratory tests as well as in-service performance testing is therefore essential, in combination with proper monitoring and analysis tools. A crucial concept is variability and the incorporation of variability in tests and analysis. In this paper we focus on t...
J Van den Bulcke, I De Windt, C Brischke, C R Welzbacher, A O Rapp, J Van Acker
Predicting the Rate of Decay, and the Potential for Misinterpretation of Proper Scientific Method
2013 - IRG/WP 13-20525
Predicting the rate of fungal attack in wood-based materials and its effect on properties remains the holy grail of wood products pathologists; however, achieving this goal is difficult because of the many variables associated with the process. This paper reviews some of the more important aspects of the decay process in relation to test methodology and then discusses how data are sometimes used b...
B S Goodell, J J Morrell
Development of a rapid method to assess the rate of fungal colonization of wood
2013 - IRG/WP 13-20531
Testing of wood durability is today done mainly with accelerated exposure tests under rather realistic conditions (in ground, outdoors with moisture traps etc). Although such tests are accelerated with respect to the conditions that outdoor exposed wood structures are exposed to, they tend to take rather long time. The present paper presents the development of a rapid method intended to assess at ...
L Wadsö
Hygroscopicity of wood after polyethylene glycol (PEG) impregnation and/or heat treatment
2013 - IRG/WP 13-40623
The hygroscopicity of wood after polyethylene glycol (PEG) impregnation and/or heat treatment was investigated by testing the water uptake, equilibrium moisture content (EMC) at various relative humidity levels, and contact angle of the poplar wood surface. The results showed that: (1) At the first moment, the heat treatment at temperatures lower than 160 ℃ did not reduce the water uptake be...
Weiyue Xu Yuan Zhu, Jinzhen Cao
Effect of the nature of the inert atmosphere used during thermal treatment on chemical composition, decay durability and mechanical properties of wood
2013 - IRG/WP 13-40625
Wood heat treatment is an attractive alternative to improve decay resistance of low natural durability wood species. Nowadays, several types of thermal treatments of wood exist. These treatments differ mainly by the nature of the inert atmosphere used to avoid wood combustion which may correspond to: nitrogen, vacuum, steam or oil. Decay resistances as well as mechanical properties are strongly co...
K Candelier, S Dumarçay, A Pétrissans, M Pétrissans, P Gérardin
Influence of Heat Treatment Medium on Fungal Resistance of Beech Wood
2013 - IRG/WP 13-40643
Hydrothermal treatment of beech wood (Fagus orientalis) performed in acidic, neutral and alkaline buffered mediums in 160 and 180°C. White rot fungi (Coriolus versicolor) and brown rot fungi (Coniophora puteana) were used to determine the influence of heat treatment mediums on the behaviour of fungal resistance. White rot of wood digest lignin rather than cellulose; while brown rot digests the ce...
A Talaei, A Karimi, M-F Thévenon
COST Action FP0904 – Increasing the Understanding of Thermo-Hydro-Mechanical Wood Behaviour and Processing
2013 - IRG/WP 13-40646
The polymeric components of wood and its porous structure allow its properties to be modified under the combined effects of temperature, moisture and mechanical action – so-called Thermo-Hydro-Mechanical (THM) treatments. Various types of processing techniques, including high temperature steam with or without an applied mechanical force, can be utilised to enhance wood properties, to produce eco...
D Jones, P Navi
The effects of copper proximity on oxalate production in Fibroporia radiculosa
2014 - IRG/WP 14-10823
Copper remains a key component used in wood preservatives available today. However, the observed tolerance of several critical wood rotting organisms continues to be problematic. Tolerance to copper has been linked to the production and accumulation of oxalate, which precipitates copper into insoluble copper-oxalate crystals, thus inactivating copper ions. The purpose of this study was to assess d...
K M Jenkins, C A Clausen, F Green III
The Physical Properties of Heat Treated Fir Wood and Outdoor Durability
2014 - IRG/WP 14-40677
Wood might be easily susceptible to degrade by biotic and abiotic factors. Therefore, wood should be protected from fungi, insects and other degradation factors by applying treatment methods. Especially, for the wood have used in the external environment. Chemical treatment methods have some disadvantages such as use of toxic chemicals (Arsenic and chromium) and treatability of refractory wood spe...
O E Özkan, H Vurdu, A Temiz, G Köse
Experiences with an industrial system for controlled thermal wood modification in pressurized unsaturated steam
2014 - IRG/WP 14-40678
Thermal wood modification in pressurized reactors has a long history, but these processes are to date industrially scarcely used, because of the relatively complicated process equipment, compared to the more common high-temperature processes in kilns at atmospheric pressure. However, based on our practical experience with the FirmoLin® process, supported by recent scientific findings, it is foun...
W Willems
A review of the analytical methods used in determining the decay resistance of heat treated wood
2015 - IRG/WP 15-40690
Heat treatment as a wood process is increasingly used because of its non-biocide behaviour and its low environmental impact. This sort of treatment is based on biopolymer chemical degradation by heat transfer. This process improves mainly the dimensional stability and the decay resistance of wood.
Wood becomes darker after this type of treatment and thus gives it an aesthetic appearance. These i...
K Candelier, M-F Thévenon, A Pétrissans, S Dumarçay, P Gérardin, M Pétrissans
Effect of natural variability of European Oak wood on heat treatment process and potential implication on wood durability
2015 - IRG/WP 15-40693
Environmental pressures appeared in France and in most European countries during the last decade has led to the development of more environmentally acceptable preservation methods. In this context, wood heat treatment has been one of the most investigated alternative method during the last years. Treated at temperatures ranging between 180 and 220°C, wood components undergo more or less important...
J Hamada, A Pétrissans, F Mothe, M Pétrissans, P Gérardin
Investigation of Dimensional Stability and Coating Performance of Different Heat-Treated Poplar Wood Before and After Accelerated Aging
2015 - IRG/WP 15-40702
In this investigation, coating performance of heat-treated poplar wood (Populus tremuloioes) in different environments, before and after accelerated aging was studied. Specimens with 150×100×20 mm and 20×20×20 mm in dimensions were prepared. Heat treatments were performed in air, steam and linseed oil media. Specimens were coated by alkyd based stain. Adhesion strength before and after aging, ...
A Talaei, D Ansari Movahed, G Rassam
Production of reactive oxygen species in the presence of oxidized iron and oxalate under conditions mimicking brown-rot fungal degradation of wood
2016 - IRG/WP 16-10861
The biochemical role of oxalate in the fungal solubilization of iron is well known, but additional information is needed on the role that oxalate plays in the brown-rot decay of lignocellulose. In this study iron sequestration from iron and iron oxide-hydroxides was assessed with regard to the function of a chelator-mediated Fenton (CMF) reaction and the generation of reactive oxygen species (ROS)...
Yuan Zhu, Liangpeng Zhuang, B Goodell, Jinzhen Cao, J Mahaney
Exudate production: a detoxification strategy of wood decaying fungi
2016 - IRG/WP 16-10868
Even often observed, the exudate production in fungi remains mainly unstudied. During growth on oak wood, the white-rot fungus Trametes versicolor produces droplets of a red-brown liquid, this phenomenom being observed with nine studied strains. One of these strains secretes a similar exudate on rich medium even in the absence of wood. This secretion seems to be linked to the formation of special...
A Deroy, J G Berrin, S Dumarçay, P Gérardin, A Kohler, D Navarro, C Rose, R Sormani, M Morel-Rouhier, E Gelhaye
Transfer of microorganisms from wooden crates to foodstuffs: assessment of a transfer threshold
2016 - IRG/WP 16-20574
Wood is commonly used in contact with foodstuffs, for example for packaging fruits or vegetables. Most common species used are beech, pine, spruce and poplar. Wood is often considered as being less safe than plastic because it is less easy to clean whereas several studies have demonstrated that microorganisms cannot survive easily on wood (Milling et al., 2005; Revol-Junelles et al., 2005). Nation...
M Montibus, R Ismail, I Le Bayon, A Jasick, M Gabille, F Aviat, V Michel, M Federighi, M Kutnik
Increasing the hardness of wood-composite panels by nanosilver
2016 - IRG/WP 16-40715
Effect of silver nanoparticles on hardness in medium-density fiberboard (MDF) was studied here. A 400 ppm aqueous nanosilver suspension was used at three consumption levels of 100, 150, and 200 mL/kg, based on the dry weight of wood fibers; the results were then compared with the control panels. The size range of silver nanoparticles was 30-80 nm. Composite mats were hot-pressed for 6, 8, and 10 m...
H R Taghiyari, J Norton, K Heidarhaee
Resistance of heat treated Ash wood under steam pressure: rot fungi, soil micro-organisms and termites
2016 - IRG/WP 16-40724
Thermal modification processes have been developed to increase the biological durability and dimensional stability of wood. The aim of this paper was to study the influence of ThermoWood® treatment intensity on wood decay resistance improvement against soil-inhabiting micro-organisms, brown/white rots and termite’s exposures. All of the tests were carried out in the laboratory with two differen...
K Candelier, S Hannouz, M-F Thévenon, D Guibal, P Gérardin, M Pétrissans, R Collet
How intraspecific radial variability of the European Oak’s may influence mild pyrolysis process and durability of the material
2016 - IRG/WP 16-40725
Last decades wood is promoted as building material. Unprotected wood exposed to outdoor conditions undergoes a variety of degradation induced essentially by fungi attacks. Heat treatment of wood by mild pyrolysis (180°C T 240°C under inert atmosphere) is a preservation process with a weak environmental impact, and therefore, is viewed as an interesting alternative to the chemical impregnation me...
J Hamada, A Pétrissans, F Mothe, M Pétrissans, P Gérardin
Dynamic mechanical analysis of viscoelastic properties of heat treated glycerol-impregnation poplar wood
2016 - IRG/WP 16-40732
The viscoelastic properties of glycerol-impregnated poplar wood after heat treatments at various temperatures were examined by dynamic-mechanical analysis. The spectra of storage modulus (E’) and loss tangent (tgδ) in the frequency at 10 Hz were measured at the temperature range from -100 to 300℃. Compared to no peak in E’ spectra and two relaxation processes in tanδ spectra of...
Li Yan
Effect of insitu polymerization on practical properties of heat treated wood
2016 - IRG/WP 16-40763
This research was conducted to investigate the effect of combined modification; heat treatment and impregnation with styrene monomer on physical and mechanical properties of poplar wood (Populus deltoides). Test samples were grouped in six levels of control, wood polymer made from styrene, heat treatment at 170 ºC and 200ºC and combined modification; first hat treated at 170 ºC and 200ºC and t...
M Ghorbani, M Mohseni Shaktaei
State of the art of industrial wood protection in Portugal
2016 - IRG/WP 16-30703
This work intended to give a perspective of industrial wood protection in Portugal. A survey was made of the companies treating wood mainly for use classes 3 and 4 such as autoclave treatments with biocides and wood modification procedures. Currently there are 23 companies with 33 production plants with an autoclave installed for wood preservation by impregnation. There are also two companies prod...
L Nunes, J Carmo, J Vicente, B Esteves