Your search resulted in 28 documents. Displaying 25 entries per page.
Ultra-structural observations on the degradation of wood surfaces during weathering
1987 - IRG/WP 2280
Radiata pine (Pinus radiata D. Don) sapwood was converted into blocks with a transverse face about 5 mm square and measuring 8 mm longitudinally. Transverse (T.S.), Radial (R.L.S.) and Tangential (T.L.S.) surfaces were prepared and specimens exposed to the weather inclined at 45° facing equatorially for periods of between 20-60 days. After 30 days exposure erosion of the middle lamella was observ...
P D Evans, S Thein
Chromium on the surface of CCA-treated wood
1978 - IRG/WP 386
Chromium in solutions of CCA preservatives is predominantly in the hexavalent state (Cr VI). It is well known that Cr VI is associated with dermatitis and skin ulceration in workers handling chromium containing products and processes. When reduced to the trivalent state, however, chromium is considerably safer. An essential part, therefore, of safety procedures in any chromium - using industry is ...
C R Coggins, P Hiscocks
Correlation between changes in colour and chemical composition during photo-degradation of wood surfaces
2005 - IRG/WP 05-40301
Changes in colour of wood (yellowing) during photo degradation or weathering reflect chemical changes in wood. Therefore, the relationship between changes in chemical composition and CIELAB colour parameters is very important to characterize photodegradation of lignocellulosic surfaces. In this study, the changes in chemical composition and yellowing due to photo-degradation was studied by expos...
K K Pandey
The possible role of mobile CCA components in preventing spore germination in checked surfaces, in treated wood exposed above ground
2001 - IRG/WP 01-30263
Untreated check surfaces are often exposed in CCA-treated lumber of refractory species used above ground since, during weathering, some checks develop beyond the preservative penetrated zone. However, decay is seldom observed in these checks even after many years of exposure. It is hypothesized that minor amounts of mobile CCA preservative components redistribute during weathering into checks, and...
S Choi, J N R Ruddick, P I Morris
The degradation of wood surfaces by water
1984 - IRG/WP 3289
Thin radial/longitudinal sections (~100 µ) of Scots Pine (Pinus sylvestris) and lime (Tilia vulgaris), were exposed to deionised water over the temperature range 25-65°C. Losses in wet tensile strength and toughness occurred rapidly at temperatures from about 50°C upwards. After about 2 months' exposure pine lost some 10-30% of its tensile strength and 20-60% of its toughness. For lime...
W B Banks, P D Evans
SEM investigation of the production of extracellular mucilaginous material (ECM) by some wood inhabiting and wood decay fungi when grown on inert surfaces
1997 - IRG/WP 97-10194
A range of wood inhabiting and wood decay fungi have been studied for their production of extracellular mucilage when grown on inert surfaces, for comparison with their growth on wood. The species tested were: Coniophora puteana, Coriolus versicolor, Chaetomium globosum, Trichoderma harzianum, Ceratocystis coerulescens, Ophiostoma piceae, Mucor sp. and Penicillium sp. They were grown on plastic me...
A R Abu, R J Murphy, D J Dickinson
Rapid loss of lignin at wood surfaces during natural weathering
1992 - IRG/WP 92-2390
Thin veneers of radiata pine (Pinus radiata D. Don) were exposed to natural weathering over a period of 30 days. Incident UV radiation was monitored at the test site. FTIR internal reflectance spectroscopy was used to study the chemical changes taking place at the veneer surface during weathering. Spectra obtained show that after only 3 days exposure there was substantial delignification at veneer...
P D Evans, K J Schmalzl, A J Michell
Mould growth at lumber surfaces of pine after kiln and air drying
1994 - IRG/WP 94-40033
Distribution of water soluble substances in green wood and later redistribution during drying is of importance for the colonisation of wood by microorganisms. According to literature the availability of nitrogenous materials is probably a major limiting factor to the microbial colonisation of wood. King et al. (1974) and Oxley et al. (1976) have shown correlation between surface nutrient concentra...
N Terziev, J Bjurman, J B Boutelje
Pretreatments of wood surfaces for improving weatherability of clear finishing
2001 - IRG/WP 01-40196
The clear film durability of wood is generally very short because of photo degradation of wood surfaces caused by UV through to the film. Pre-treatment of wood surfaces for protecting against photodegradation is very important for clear finishing system. In this study, some pre-treatments, ie; polyethylene glycol (PEG) and UVA grafting (2-hydroxy-4(2,3-epoxypropoxy) benzophenone (HEPBP)), were app...
M Kiguchi, Y Karaoke, P D Evans, Y Kadegaru, Y Imamura
A quantitative weathering study of wood surfaces modified by chromium VI and iron III compounds
1989 - IRG/WP 2330
Thin veneers of Pinus radiata were treated with dilute aqueous solutions of chromium VI and iron III compounds and exposed to natural weathering for 35 days. Zero-span tensile strength and weight losses of treated veneers were compared with losses observed in untreated specimens In a study designed to demonstrate the applicability of strength and weight loss measurements to the rapid quantitative ...
P D Evans, K J Schmalzl
Dominant genera of fungi isolated from the surfaces of Sugi (Cryptomeria japonica D. Don) heartwood lumbers exposed at six test sites from northern to southern regions of Japanese islands
1999 - IRG/WP 99-10304
The surfaces of wood materials are disintegrated not only by sunlight and rainwater but also by microbes when exposed above ground condition. This paper deals with the investigation of fungi isolated from the surfaces of Sugi heartwood lumbers (W100 by T10 by L300 mm) exposed at an angle of 45° without ground contact for 16 months at the six test sites from northern to southern regions of Japan. ...
S Doi, M Mori, M Kiguchi, Y Imamura, M Hasegawa, S Morita, S Nakamra, Y Kadegaru
The degradation of wood surfaces by dilute acids
1985 - IRG/WP 3326
Thin radial/longitudinal sections(~100 µ) of Corsican Pine (Pinus nigra) and Lime (Tilia vulgaris), were exposed to Sulphuric, Sulphurous, nitric, acetic, and formic acid at 40°C in the pH range 2-6. After about 3 months exposure to Sulphuric, nitric, acetic and formic acid at pH 2.0 Pine lost some 20-25% of its tensile strength. Losses in tensile strength due to sulphurous acid were greater bei...
P D Evans, W B Banks
Effects of bleaching process on the roughness values of wood surfaces of Lebanon cedar (Cedrus libani A. Rich.) and Black poplar (Populus nigra L.) using NaOH (sodium hydroxide), H2O2 (hydrogen peroxide) and Ca(OH)2 (calcium hydroxide)
2008 - IRG/WP 08-40403
Technical progress in the wood industry has been rapid in recent times. In this case, the quality assurance of the consumer products aligned with aesthetics value appears as one of the most important parameters. Because of the outer appearance of goods exert an effect on customers, interest in production of high quality surfaces of wooden commodities has increased essentially based on the surface ...
I Usta, E Aydinlar
Colour change monitoring of photodegradation in Scots pine (Pinus sylvestris) – a short term focus
2009 - IRG/WP 09-40442
Colour change monitoring of photodegradation is a quick and easy method for monitoring rates of photodegradation in timber. A study was undertaken to compare this technique to other monitoring methods, including microtensile strength changes and weight loss. Colour changes due to accelerated sunlight exposure were monitored using a Datacolor check spectrophotometer and compared with a set of contr...
V Sharratt, C A S Hill, D P R Kint
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
Preliminary Observations of the Photostabilization of Wood Surfaces with Cerium Oxide Nanoparticles
2010 - IRG/WP 10-40504
Reactive transition metal compounds, wood modification and grafting of UV absorbers have all been used to photostabilize wood. Some of these approaches are promising, but the toxicity of certain reactive transition metal compounds and the cost of wood modification and grafting have restricted their commercial applications. Hence, more cost-effective and environmentally friendly methods of protecti...
Chunling Liu, A Ahniyaz, P Evans
Using an accelerated laboratory method to evaluate Aureobasidium pullulans colonization on painted surfaces and underlying wood substrate
2012 - IRG/WP 12-20480
Mold growth on painted surfaces can lead to premature paint film failure and is unsightly. Aureobasidium pullulans has been identified as a major cause of black stain on surfaces painted with acrylic or latex paints. In this study, an accelerated laboratory method developed by Zabel and Horner (1981) was used with modifications to the type of agar used and sample evaluation methods. A study was ...
C Schauwecker, L Burns, A Preston
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
Protective nanoparticle coating reducing water absorption of wood species
2012 - IRG/WP 12-40614
Nanoparticle coatings were deposited onto different tropical wood samples for controlling the surface hydrophobicity. The styrene(maleimide) nanoparticles were synthesized in aqueous dispersions under pure conditions or in combination with 70 wt.-% palm oil. A first evaluation of the non-coated wood surfaces indicates a high dependence between the water contact angles, the average surface roughnes...
P Samyn, A Paredes, G Becker, H Van den Abbeele, L Vonck, D Stanssens
Influence of coatings on water uptake of wood surfaces before and after natural and artificial weathering
2013 - IRG/WP 13-40641
Liquid water absorption of wood surfaces with and without coating, before and after exposure to artificial and natural weathering has been studied. Spruce, oak and sapele samples have been exposed to the cycle of EN 927-6, to the cycle of the Gardner wheel and to natural weathering. Five coatings were tested including solventborne and waterborne, semi-transparent and opaque products. Exposure to w...
L Podgorski, S Collignan, J-D Lanvin
Colorimetric evaluation of three tropical woods after accelerated weathering
2014 - IRG/WP 14-20541
The use of wood in the furniture industry is directly associated with their physical, mechanical and organoleptic characteristics. The color of the wood is a major factor in the selection of forests species to employ in the furniture projects and is fundamental the maintenance of its colorimetric pigments over time. The objective of this study was to evaluate the colorimetric behaviour of three tr...
R Faustino Teles, A Florian da Costa
Influence of Exposure Direction on Leaching of a Biocide from Painted Wood Surfaces
2014 - IRG/WP 14-50303
The objective of this project was to investigate the influence different exposure directions – North, East, South and West on the cumulative quantity of a biocide leached from painted wood surfaces due to rainfall and the consequences for the risk assessment.
The study included a solvent-borne primer without biocides and a topcoat protected with a biocidal active substance. Both products were a...
M Klamer
Effects of UV Radiation on Melanization and Growth of Fungi Isolated from Weathered Wood Surfaces
2015 - IRG/WP 15-10842
This research tests the hypothesis that fungi isolated from weathered wood will respond to elevated levels of UV radiation by increasing their melanin production. To test this hypothesis, we measured the melanin production and mycelial color of Aureobasidium pullulans and Cladosporium cladosporioides, before and after the fungi were grown under artificial UV, visible light and complete darkness. T...
V A Hernández, P D Evans
Fungal growth on coated wood exposed outdoors: influence of coating pigmentation, cardinal direction and inclination of wood surfaces
2017 - IRG/WP 17-10896
The objective of the SERVOWOOD project was to develop and establish European Standards that will facilitate the prediction of service life for exterior wood coatings. One of the objective of this project was to study fungal growth of the field exposed panels. Two coatings applied in 2 and 3 coats were exposed for one year outdoors at 45° south: one solventborne (alkyd based) and one waterborne (a...
L Podgorski, C Reynaud, M Montibus