Your search resulted in 185 documents. Displaying 25 entries per page.
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
Effectos de la intemperización artificial sobre la madera de mezquite (Prosopis laevigata)
2008 - IRG/WP 08-40430
The effects of artificial weathering on Prosopis laevigata wood were studied on eight replicates (150 x 72 x 15mm (l x t x r)) free of knots, cracks and resin. The samples were exposed tangentially to UV light and to water spray during three cycles (1 cycle corresponded 1 week of artificial weathering). The conditioning time between each cycle was thirty days. The effects were measured according t...
A Carrillo-Parra, F Hapla, C Mai
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
Component leaching from CCA, ACQ and a micronized copper quat (MCQ) system as affected by leaching protocol
2009 - IRG/WP 09-50261
Leaching results for Cu, Cr and As (CCA) and Cu (ACQ and MCQ) from southern pine are compared for laboratory tests (AWPA E11, and draft OECD methods I and II) and natural weathering of horizontally and vertically oriented lumber samples over two seasons. This paper expands on results and comparison of results presented at the IRG regional meeting in Costa Rica in Dec 2008 (Cooper and Ung 2008) a...
P A Cooper, Y T Ung
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
Selection of an appropriate coating system for wooden boats to be used in fresh water
2009 - IRG/WP 09-40472
Properties of several, most commonly used protective low-price coatings, which are used by the pletnja boat owners in Bled, Slovenia, were extensively studied. The aim of this professional, practically oriented study was to compare various coating systems, and to recommend the most suitable one to the boat owners. Regarding specific use conditions, the following properties, including their resista...
M Petrič, B Kričej, A Logar, M Pavlič
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
The Use of Micro-Tensile Testing to Assess Weathering Decay and Oxidative Degradation of Wooden Items
2010 - IRG/WP 10-20433
This paper presents a method to study the weathering performance of wooden items and to assess the oxidative degradation of wood via the Fenton reaction. Weathering resistance and photo-stability of wood was tested using pine wood (Pinus sylvestris) veneer strips measuring approximately 60 µm in thickness. The veneer strips were treated using a reactive chemical to impart surface protection. The ...
C Mai, Yanjun Xie, Zefang Xiao, P D Evans, H Militz
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
Effect of Coatings on the Durability of Birch and Spruce Plywood. Part 1: Weathering Performance
2010 - IRG/WP 10-40526
Several different coated birch and spruce plywood types were investigated in Finland using outdoor weathering. The weather performance of the tested coated birch plywood was good compared with uncoated birch and spruce plywood. The paint base film coated and painted birch plywood performed well in outdoor testing at VTT's test site. Phenol film coated plywood was sensitive to UV light, but on...
A Nurmi, H Viitanen
Effect of Coatings on the Durability of Birch and Spruce Plywood. Part 2: Biological Durability
2010 - IRG/WP 10-40527
Several different coated birch and spruce plywood types were investigated in Finland using the combination of outdoor weathering and decay test EN 12038. The most important factor to affect on the biological performance of birch plywood, coated and uncoated, was edge sealing. For spruce plywood edge sealing had a smaller effect. However, in spite of positive effect against decay, edge sealing did ...
A Nurmi, H Viitanen
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
The Effectiveness of Machined Profiles at Reducing the Checking of Wooden Decking
2011 - IRG/WP 11-40541
This study tests the hypothesis that ‘the ability of surface profiling to reduce checking of deck boards exposed to weathering will vary with wood species and profile type’. Southern pine (Pinus sp.) and Pacific silver fir (Abies amabilis) deck boards were machined to produce three different types of surface profiles: flat (control), ribbed (V-shaped grooves), and rippled (U-shaped grooves). B...
P Evans, I Cullis, P Morris
Evaluation of an optimized industrial process aiming to improve the natural durability and mechanical behavior of bamboo for outdoor use
2011 - IRG/WP 11-40554
Mao Bamboo (Phyllostachys pubescens) is characterized by high contents of sugar and starch and by high hygroscopicity, which makes it susceptible to biodegradation, and specifically to fungal decay. Still, many bamboo based products regularly enter the European wood construction market, competing with traditional solid wood products used for outdoor decking and cladding. The performance of a heat ...
F Simon, M Kutnik, I Le Bayon, G Moisset, V Gatimel
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