Your search resulted in 3076 documents. Displaying 25 entries per page.
Service life prediction of wood: scale-dependent tools within a bio-engineering framework
2008 - IRG/WP 08-20387
Service life prediction (SLP) is a complex yet essential method for the building industry. Accurate and precise assessment of the components is crucial for a strong position of wood on the market. As it is a biological material, wood has an inherent variability and is susceptible to fungal attack. Therefore a profound knowledge of these characteristics is the corner stone of SLP for wood products....
J Van den Bulcke, J Van Acker, M Stevens
Development of a Weatherometer to Accelerate the Surface Checking of Wood
2008 - IRG/WP 08-20388
There is significant interest in developing preservatives that are better at preventing wood from checking. Currently, however, there is no accepted test methodology for accelerating the development of checks in wood samples so information on the effectiveness of treatments at restricting checking can be obtained more quickly. This paper describes the development of a new type of weatherometer (Ac...
R Ratu, P D Evans
Bi-oleothermal treatment of wood at atmospheric pressure: resistance to fungi and insects, resistance to weathering and reaction to fire results
2008 - IRG/WP 08-40418
Bi-oleothermal process is a simple treatment which has been developped by CIRAD in cooperation with FCBA. It allows a deep impregnation of wood with hydrophobic products using cheap facilities. The process includes two steps at atmospheric pressure. The first one is a dipping of wood samples in a hot oil bath (between 110 °C and 200°C) which creates an overpressure inside the wood. The second on...
L Podgorski, I Le Bayon, I Paulmier, J-D Lanvin, V Georges, D Grenier, H Baillères, J-M Méot
The Effects of Solar Radiation on the Fungal Colonization and Color of Weathered Wood
2008 - IRG/WP 08-10676
Solar radiation rapidly depolymerizes lignin at wood surfaces exposed outdoors producing a suite of low molecular weight aromatic compounds within weathered wood. Fungi colonizing weathered wood are able to metabolize these aromatic compounds, and many of them also contain high levels of melanin to protect themselves from the harmful effects of UV radiation. Both of these adaptations suggest that ...
V Hernandez, C Breuil, P D Evans
Accelerated weathering of nine tropical wood species from Cameroon
2009 - IRG/WP 09-10705
The natural durability of tropical species for building components has been a subject of recent concern and questioning, mainly the resistance to weathering. Weathering resistance of nine tropical species from Cameroon, namely Azobe, Bilinga, Bubinga, Teak, Dousie, Moabi, Musanga, Sipo and Padauk were evaluated using an accelerated weatherometer for 2016 hours. Measurement of moisture fluctuation,...
S Pankras, Jinzhen Cao, D P Kamdem
Use of Confocal Profilometry to Quantify the Weathering of Wood
2009 - IRG/WP 09-20421
The methods that have been used to screen chemicals for their ability to prevent the weathering of wood involve assessing the loss in weight and tensile strength of treated wood veneers or measuring the rate of erosion of exposed and unexposed (masked) wood subjected to weathering. The erosion of wood during natural weathering occurs slowly and long exposure times are required to produce differenc...
Chunling Liu, P Evans
Investigation of chemical changes in acetylated beech wood during weathering
2009 - IRG/WP 09-40460
In this study Beech wood (Fagus orientalis) acetylated and has been subjected to a variety of artificial weathering conditions (water only, light only, water and light together)in difference times (0,50,150 and 300 h), then wood surface analyzed using Fourier Transform Infrared spectroscopy (FTIR).Results shown that weathering process affected the functional groups on the wood surface. Light and w...
M Akhtari, M Arefkhani
Weathering of Wood Modified with the N-Methylol Compound 1,3‑dimethylol-4,5-dihydroxyethyleneurea (DMDHEU)
2009 - IRG/WP 09-40467
Scots pine (Pinus sylvestris L.) sapwood boards were treated with a methylated 1,3‑dimethylol-4,5-dihydroxyethyleneurea (mDMDHEU) causing weight gains of approx. 25% and exposed to weathering for 18 months. Compared to untreated boards, treatment with mDMDHEU reduced surface discoloration mainly caused by staining fungi. Boards treated with mDMDHEU exhibited clearly lower moisture content th...
C Mai, Yanjun Xie, A Krause, K Urban, P D Evans, K Richter, H Militz
A fast and economic method to produce grey wooden surfaces for decking and cladding: preliminary results
2009 - IRG/WP 09-40474
Uncoated wood is commonly used in France for cladding and decking to minimise maintenance. However wood surfaces progressively turn grey due to exposure to sunlight and water. This grey colour develops after several months depending on the wood species and the exposure: in the northern hemisphere surfaces facing south and west are most exposed and turn grey more rapidly than those facing north and...
L Podgorski, V Georges, I Garmendia, B Sánchez Sarachu
Early detection of colonisation by blue stain and mould on modified wood using PCR technique
2010 - IRG/WP 10-10730
The aim of this research was the early detection of fungal attack on the surfaces of modified and unmodified wood after natural weathering. The investigation was carried out by molecular techniques and the development and establishment of genus/species specific PCR for important moulds and sapstain fungi was part of this work. After adaption of the method, a monitoring of the succession of Ascomyc...
A Steitz, B Schmöllerl, N Pfabigan, S Bollmus, G Grüll
Finite Element Modelling of the Checking of Wood Exposed to Accelerated Weathering
2010 - IRG/WP 10-20459
The surface checking that develops when wood is exposed to the weather reduces the visual appeal of treated wood products and can reduce the effectiveness of preservative treatments. There is strong interest in developing solutions to this problem and also a growing realization that such solutions may evolve from a deeper understanding of the mechanisms responsible for surface checking. In this pa...
S G Ribarits, P D Evans
Photostabilization of Wood with Higher Molecular Weight UV Absorbers
2010 - IRG/WP 10-30524
Higher molecular weight UV absorbers were created by reacting the epoxy-functionalized UV absorber 2-hydroxy-4(2,3-epoxypropoxy)-benzophenone (HEPBP) with maleic, phthalic or succinic anhydride. The ability of the UV absorbers to photostabilize wood was then examined. FTIR-spectroscopy confirmed that HEPBP reacted with phthalic anhydride to create a polyester that preserved the UV-absorbing benzop...
P D Evans, M J Chowdhury
Distribution and availability of preservative components in ACQ treated wood - effects of coatings and weathering
2010 - IRG/WP 10-30537
Copper and quaternary ammonium compound (quat) distributions across lumber (gradients) and availability, as measured by amount removed by intensive leaching of wood flour, were measured in ACQ treated southern pine lumber. Samples were evaluated just after treatment and stabilization, or after 3 years of laboratory storage, or after 3 years of natural weathering exposure. The objective was to in...
T Ung, M Nejad, P Cooper
The Effects of Natural Weathering on the Properties of Heat Treated Alder Wood
2010 - IRG/WP 10-40484
Heat treatment is an effective method to improve the dimensional stability and biological durability of wood. The heat treatment technology and the heat treated wood products were recently introduced to Turkey. However, only a few studies have been reported on the effect of natural weathering on the properties of heat treated wood in both Turkey and the world. In this study, heat treated alder (Al...
S Yildiz, Ü C Yildiz, E D Tomak
Comparison of colour change in wood clear-coating systems including inorganic and organic UV absorbers for exterior use
2010 - IRG/WP 10-40499
The aim of this work is to compare the performance of inorganic and organic UV absorbers used in a wood coating application against weathering. Our study has investigated the colour changes of selected UV absorbers; hombitec 402 RM from the Sachtleben Company as an inorganic UV absorber, tinuvin 477 DW from the Ciba Company as an organic UV absorber. The study was carried out on two wood species; ...
Ö Özgenç, B Forsthuber, A Teischinger, C Hansmann
Performance of selected types of coated and uncoated modified wood in artificial and natural weathering
2010 - IRG/WP 10-40510
The objective of the present work was to investigate the influence of commercial wood modification methods on weathering behaviour and coating performance. It was aimed to compare modification methods and to set up maps of weathering behaviour for these methods with and without a semi-transparent wood stain. Artificial and natural weathering trials were carried out with a selection of different ty...
G Grüll, L Podgorski, M Truskaller, I Spitaler, V Georges, S Bollmus, A Steitz
Study of Microscopy Properties of Modified Wood During Weathering Process
2010 - IRG/WP 10-40517
In this study spruce (Picea excelsa) and Beech (Fagus orientalis) wood acetylated and has been subjected of artificial weathering in difference times (0, 50,150&300 h), then wood surface analyzed using Scanning Electron Microscopy (SEM). The SEM results shown that the surface of wood exposed to weathering undergoes distinct physical changes and the surface degradation appears to be directly propor...
M Akhtari
Impact of wood species on the performance of exterior wood coatings
2010 - IRG/WP 10-40519
To prolong the service life of a wooden construction the protective function of a coating is of utmost importance. The chemical composition as well as the wood-coating interface affects the performance of this protective layer and obviously wood species have an impact too. This paper discusses the influence of wood species on the overall coating performance. Therefore, a range of opaque waterborne...
I De Windt, J Van den Bulcke, J Van Acker
Lignin blocking effects on weathering process of wood plastic composites
2010 - IRG/WP 10-40529
The weathering of wood–plastic composites (WPC) causes discoloration which affects their aesthetic aspects. It has been proved that these discolorations are due to lignin degradation. Effects of blocking the susceptible structure of lignin assessed by chemical treatment such as acetylation and methylation are reported in this study. Surface chemical change of wood plastic composite (WPC) formula...
P Darabi, A Naghi karimi, S Ahmade Mirshokraie, M-F Thévenon
Moisture protection and performance during 5 years exposure of 19 wood coating systems on a cladding in Vienna
2011 - IRG/WP 11-40561
A cladding with vertical boards of Norway spruce (Picea abies) comprising different coating systems had been exposed to natural weathering oriented south west in Vienna for 5 years. Weathering behaviour of the boards was assessed in intervals and wood moisture content was measured over the first 22 months of exposure. The moisture protective properties of the coating systems were assessed using la...
G Grüll, I Spitaler, M Truskaller
Wet and dry adhesion of coatings on modified and unmodified wood: influence of 18 months of natural weathering on the pull-off test and cross-cut test results
2011 - IRG/WP 11-40569
The objective of this paper is to study the influence of several types of modification (acetylation, furfurylation, heat treatment) on coatings adhesion after 18 months of natural weathering according to EN 927-3 in Vienna (Austria).
The paper compares two methods for assessing the adhesion: the cross-cut test (EN ISO 2409) which is the conventional method used and recommended in EN 927-3 and th...
L Podgorski, G Grüll, M Truskaller, J D Lanvin, S Bollmus
Use of Variable Pressure Scanning Electron Microscopy for in situ Observation of Degradation of Wood Surfaces during Artificial Weathering
2012 - IRG/WP 12-20489
Variable pressure scanning electron microscopy (VPSEM) is capable of observing electrically non-conductive materials like wood without the need to render the surface conductive by applying a coating of gold, platinum or carbon. Hence, there is the possibility that VPSEM could be used to non-destructively follow the structural changes occurring at wood surfaces during weathering, because specimens ...
F Hatae, Y Kataoka, M Kiguchi, H Matsunaga, J Matsumura
Water uptake of wood surfaces with and without coating: influence of weathering
2012 - IRG/WP 12-40580
The objective of this study was to compare liquid water absorption of wood surfaces with and without coating, before and after artificial weathering. Samples of spruce, oak and sapelli were exposed to the EN 927-6 cycle for 1500 and 1850 hours and to the weathering produced by the Garner wheel for 1000 hours. Two highly pigmented coatings (solventborne and waterborne) and two semi-transparent stai...
L Podgorski, S Collignan, J D Lanvin
Comparison of exterior performance of two coating systems based polyurethane applied Pinus sylvestris L. and Picea orientalis L. wood
2012 - IRG/WP 12-40588
Some surface changes in sapwood and heartwood of two species before applying clear-coating were characterized after accelerated weathering time. Wood specimens covered with two types polyurethane (PU) films were also observed in accelerated weathering exposure. In this study, changes on the wood surface were compared of between wood specimens covered with two types polyurethane (PU) films after ir...
Ö Özgenç, Û Cafer Yıldız
Determination of the natural durability of solid wood against wood-destroying fungi - a European round-robin test
2013 - IRG/WP 13-20511
In Europe the durability of wood against wood-destroying basidiomycetes is tested according to CEN/TS 15083-1 (2005). Hitherto existing experience with this standard is quite heterogeneous and results from previous round-robin tests have stayed unreported or have been reported incompletely. In particular the need for natural pre-weathering of the test specimens to allow potential detoxification of...
C Brischke, C R Welzbacher, A Gellerich, S Bollmus, M Humar, K Plaschkies, W Scheiding, G Alfredsen, J Van Acker, I De Windt