Your search resulted in 162 documents. Displaying 25 entries per page.
Testing a diffusion and reaction model for the leaching of CCA components from unfixed CCA-treated wood
2002 - IRG/WP 02-50193
A previously described physical model applicable to the leaching of any substance undergoing a first-order fixation reaction with wood is applied to the leaching of CCA components from unfixed wood. Using this model and laboratory leaching experiments with small wood samples immersed in water, the diffusion coefficients and reaction rate constant of Cr6+, total Cr, Cu and As in unfixed CCA-treated...
L Waldron, P A Cooper
Comparison of Temporal Changes in Metal Leaching and Aquatic Toxicity from Wood Treated with CCA and Alternative Preservatives
2005 - IRG/WP 05-50236
This study compares the temporal variation of chemical leaching and aquatic toxicity of wood treated with chromated copper arsenate (CCA) and other copper-based wood preservatives (alkaline copper quaternary (ACQ), copper boron azole (CBA), copper citrate (CC) and copper dimethyldithiocarbamate (CDDC)). Treated wood blocks were leached for 21 days and the leachate collected was analyzed for prese...
B Dubey, T G Townsend, G Bitton, H M Solo-Gabriele
A diffusion and reaction model for the leaching of Cr-VI from unfixed CCA-treated wood
2001 - IRG/WP 01-50169
A physical model applicable to the leaching of any substance undergoing a first-order fixation reaction with wood is presented. Using this model and a laboratory leaching experiment with small wood samples immersed in water, the radial and tangential diffusion coefficients and the reaction rate constants of Cr-VI in unfixed CCA-treated red pine (Pinus resinosa Ait.) are measured. Reaction rate con...
L Waldron, P A Cooper
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
Solvent drying and preservation of timber
1977 - IRG/WP 381
Processes which combine drying and preservation are first reviewed. Some preliminary experiments are then described in which blocks of green Sitka spruce sapwood were immersed, in a solution of tributyltin oxide (TBTO) in methanol at 60°C. Satisfactory penetration of the preservative and exchange of methanol and water occurred in a few hours. The methanol was removed rapidly from the wood by evap...
J A Petty
Sequestration of copper ions by the extracellular mucilaginous material (ECMM) of two wood rotting basidiomycetes
2004 - IRG/WP 04-10533
The radial growth rate of colonies originating from either whole or ECMM-free inocula of Coriolus versicolor was investigated. The presence of ECMM allowed colonies to maintain higher growth rates than those form ECMM-free inocula up to 2 mM CuSO4 in the medium. The ECMM of C. versicolor and G. trabeum was able to reduce the diffusion of copper ions in solution. The ‘raw’ ECMM of both fungi ha...
D Vesentini, D J Dickinson, R J Murphy
Aspects of diffusion of boron through wood
1984 - IRG/WP 3298
Boron compounds have been shown to be toxic to a wide range of wood destroying insects and fungi. They are cheap, have low mammalian toxicity and their application in the treatment of wood does not demand specialized equipment. These attributes make them specially attractive to developing countries. Currently, however, little is known about the mechanism of diffusion of boron through wood. Effecti...
S Iddi
Performance of treated fence posts after 6 years in five test plots in the State of Sao Paulo - Brazil
1976 - IRG/WP 376
Fence posts treated with creosote, pentachlorophenol and creosote/ pentachlorophenol mixtures showed good performance after 6 years of exposure in five test plots located in the State of Sao Paulo - Brazil. Good results were also achieved with copper sulphate/sodium arsenate and copper sulphate/potassium dichromate mixtures. Fungi and termites were the main destroying agents found attacking the po...
M S Cavalcante
Synergistic effect of boron on Streptomyces rimosus metabolites in preventing conidial germination of sapstain and mold fungi
1992 - IRG/WP 92-1565
We evaluated the synergistic effect of boron (4% BAE solution of Tim-Bor or 4% boric acid) on Streptomyces rimosus metabolites in preventing spore germination of sapstain and mold fungi using plate bioassay, Southern yellow pine and sweetgum block tests, and green pine log sections: sapstain -- Ceratocystis coerulescens, Ceratocystis minor, and Aureobasidum pullulans; mold fungi -- Aspergillus nig...
S C Croan, T L Highley
Non-pressure treatability of plywood by CCA, CCB and boron
2005 - IRG/WP 05-40295
Study on diffusibility and absorbability of CCA, CCB and boric acid in 3 mm thick 3-ply hardwood plywood at water saturated and air-dry conditions and dipped at same concentration (5%) and same duration of time (12 hours) revealed complete diffusion of all the preservatives at water saturated condition. Only the CCA-C was found absorbed by the plywood at air-dry condition. The rate of absorption a...
A K Lahiry
Soft rot cavity widening - A consideration of the kinetics
1984 - IRG/WP 1227
Studies on the micromorphology of soft rot cavity formation by Phialophora hoffmannii in birch using time-lapse cinemicrography are briefly outlined. A mathematical model is constructed to describe the cavity widening process, particularly changes in the surface area of a hypothetical cavity during enlargement. On comparison with observed data it is concluded that the rate of cavity widening is de...
M D C Hale, R A Eaton
Borate thermal treatments
1992 - IRG/WP 92-3715
Green, partially seasoned (air-dried, steam conditioned), or kiln-dried southern pine timbers were treated thermally using 15% disodiumoctaborate tetrahydrate solution. After treatment, sections were stored under non-drying conditions to allow for diffusion. Results showed that effective treatment meeting the AWPA minimum retention (0.17 B203 pcf [2.72 kg/m³] in the outer inch) and penetration (2...
H M Barnes, R W Landers, L H Williams
What information can we glean from field testing
1995 - IRG/WP 95-20057
To mathematically compare the performance of preservatives in a field test, equations were formulated to describe the relation between log score and time and between rate of decay and retention. By combining these equations, a model was derived for the performance of a number of waterborne preservatives. Some relations between the estimated parameters for different preservatives were noted and the...
P I Morris, S Rae
Preservative treatment of Eucalyptus saligna fence posts by the double-diffusion method
1982 - IRG/WP 3196
Eucalyptus saligna fence posts treated by the double-diffusion method with two chemical combinations showed average lives of 11.2 years (copper sulphate and potassium dichromate at 10.5 kg/m³ retention)and of 14.3 years (copper sulphate and sodium mono-H arsenate at 7.1 kg/m³ retention), as determined in five test sites in the State of Sao Paulo, Brazil. The exponential model was the best fit wh...
E S Lepage, A R De Freitas
Options for accelerated boron treatment: A practical review of alternatives
1985 - IRG/WP 3329
Boron wood preservatives are almost exclusively applied by momentary immersion and block diffusion storage. Alternative techniques are described which can be used to accelerate boron treatment. Diffusion coefficients have been derived to define the acceleration of diffusion with increasing temperature. Schedules are described for pressure impregnation of green timber, involving steam conditioning,...
P Vinden, T Fenton, K Nasheri
Fluorine compounds for wood preservation
1971 - IRG/WP 304
Fluoride compounds have gained a considerable importance in wood preservation, especially in Germany and some other countries of Europe. They are used as single compounde or in mixtures of different compounds. In the International Research Group on Wood Preservation which continues the activities of a former OECD-Group, it was moved to prepare a survey on fluorides in wood preservation together wi...
G Becker
Finite element analysis of boron diffusion in wooden poles
2003 - IRG/WP 03-40263
The problem of describing the migration of dissolved boron in wood is treated with special reference to the commonly used remedial treatment of wooden poles. The governing equations are derived and discussed together with some of the material parameters required. The equations are solved by the finite element method and finally, results showing the effect of different treatment strategies are pres...
K Krabbenhøft, P Hoffmeyer, C G Bechgaard, L Damkilde
Questionnaire pour la préparation de fiches monographiques pour les champignons lignivores
1972 - IRG/WP 103 F
C Jacquiot
Treatment of dried sawn spruce and redwood building timbers with water-borne preservatives under a scheme for the quality control of the preservation and preserved wood in the Netherlands
1978 - IRG/WP 3123
Treatment of dried sawn spruce and redwood Building Timbers with water-borne preservatives under a scheme for the quality control of the preservation and preserved wood in the Netherlands. The aim of this article is to give the reader a modest description of the evaluation of fundamental research in wood preservation into a practical application....
H F M Nijman, N Burgers
Some wood-destroying Basidiomycetes. Volume 1 of a collection of monographs
1981 - IRG/WP 1121
One of the first tasks of the International Research Group on Wood Preservation, when it began its work in 1969, was to compile a series of reports on the common decay fungi which can attack wood. This volume, which contains the first of these reports, has been compiled with the help of mycologists and wood preservation specialists in France, Ghana, the Federal Republic of Germany, the Netherlands...
R Cockcroft
The utilization of preserved rubberwood
1982 - IRG/WP 3186
The paper examines the use of processed and kiln-seasoned rubberwood for manufacturing furniture and doors and windows, discusses methods tested and found acceptable for preserving the timber as well as for drying the treated timber in conventional kilns. It considers a type of furniture where narrow width timber of preserved and kilned rubberwood has been used with great success. It recommends th...
V R Sonti, B Chatterjee, M S Ashraf
Time dependent over-uptake of etherificated melamine resins
1998 - IRG/WP 98-40109
Waterbased methanol-etherificated melamine-formaldehyde resins can increase the fungal resistance of the treated wood though they are known to be non-toxic. Therefore melamine-resins are at the present an object of research activities of European projects and of some companies. The paper highlights the importance of quoting the duration of the diffusion when immersed in the treating solution, as m...
D Lukowsky, R-D Peek
Diffusion of fused borate rods in top ends of poles
1989 - IRG/WP 3518
Diffusion tests of fused borate rods were carried out on extremities of sapwood poles in service. Rods were set in drills under the cone with or without addition of liquid Boracol 40. After one year of weathering, a good diffusion in the slice under the cone and even below the slice and in the cone itself was observed in Scots pine and spruce poles. The rods were still intacts and constitute, in f...
D Dirol, J P Guder
The internal-external diffusion process: Table salt treated poles
2005 - IRG/WP 05-50224-25
This new technique of preservation of wooden poles consists of keeping preservative in stock, in a reservoir drilled inside the pole, in its whole length.
This permits the use of non toxic, common products such as table salt, grease, etc, in the preservation of utility poles, building columns, or the like.
Some major obstacles to a good implementation of a good preservation with the classical pr...
L Nitunga