Your search resulted in 24 documents.
The course of fixation of Cu-Cr-As wood preservatives
1972 - IRG/WP 307
Copper-chrome-arsenic (CCA) preservatives in contact with wood result in an instant extensive increase of pH, because of ion-exchange and adsorption reactions with the wood. During precipitation of the active elements the pH continuously increases but reaches a maximum, when all chrome is consumed. Some of the early reaction products are unstable and slowly convert via dissolution into stable comp...
S-E Dahlgren
Collaborative tests on the influence of solvent and drying method on the toxic limit of wood preservatives against Basidiomycetes
1974 - IRG/WP 248
Seven institutes from five countries, Austria, England, France, Germany and the Netherlands have collaborated in a study on the influences of solvent and drying method on the toxic limits of wood preservatives against Basidiomycetes tested according to the agar-block method. Two preservatives, a 25% pentachlorophenol-concentrate and tributyltinoxide were applied to pine sapwood and beech and teste...
T Hof
CCA Chemistry
1983 - IRG/WP 3268
A Pizzi
Inhibition of wood decay and termite damage by calcium precipitation
1996 - IRG/WP 96-30111
Fungal decay of wood in service, especially brown rot, results in billions of dollars (US) of losses annually. Recent environmental restrictions, both U.S. and international, are limiting or eliminating the use of broad spectrum biocides for wood preservation, primarily due to problems with disposal. In order to design new, environmentally benign methods for control of wood decay fungi, it is esse...
F Green III, T A Kuster, L Ferge, T L Highley
Environmentally more acceptable solvents
1979 - IRG/WP 3131
The subject of this paper is hydrocarbon solvents with particular reference to the cyclo-aliphatic or naphthene-rich, grades which are now available. The specialised low aromatic high boiling petroleum fractions are also discussed....
A M Cumbers
Inhibition of termite damage by N'N-napthaloylhydroxyamine (NHA): Reticulotermes flavipes (Kollar) vs. Coptotermes formosanus Shiraki
2000 - IRG/WP 00-10354
The calcium precipitating agent NHA has been shown to protect southern yellow pine (SYP) from wood decay and termite damage comparable to CCA in field tests (Gulfport, MS) for two years (Crawford and Green, 1999). In a collaborative study, SYP wood blocks were vacuum treated with three concentrations of aqueous NHA and exposed in a no-choice test to Eastern subterranean termites (FPL, USA) and For...
F Green III, S T Lebow, T Yoshimura
Ability of chitosans to limit wood decay under laboratory conditions.
2004 - IRG/WP 04-30339
Chitosans have recently been explored for controlling a number of plant pathogenic fungi and have shown some promise for controlling stain fungi on wood. The potential for using chitosans either alone or in combination with copper sulfate to protect wood from fungal decay was explored using maple veneers. Chitosan treatment reduce weight losses caused by two brown rot and one white rot fungi, howe...
M Maoz, J J Morrell
A comparison of the leaching resistance of diammine-copper complexes and copper carbonate precipitated in wood
1997 - IRG/WP 97-30158
Previous studies have shown that during treatment of wood with ammoniacal copper solutions, both simple copper precipitates and diammine-copper complexes are formed. The objective of the present study is to determine the relative importance of both forms of copper, on such aspects as preservative leachability and biological performance. In the current experiment, the leachability of copper carbona...
Xiao Jiang, J N R Ruddick
Unsuitability of the limiting dose as a criterion for assessing the toxicity of preservatives to wood-destroying fungi
1974 - IRG/WP 243
In the majority of methods for investigating preservatives for wood-destroying fungi their toxicity is assessed by determining what is called the "limiting dose". This normally denotes a range of preservative solution concentrations or retentions of dry preservative in the timber, the lower value serving to indicate the amount of preservative at which is observed the expected effect, e.g. the grow...
D A Belenkov
Giftwirkung einiger organischer Zinn-Verbindungen auf Eilarven von Hylotrupes bajulus (L.). [Toxic efficacy of some organic tin compounds against egg larvae of Hylotrupes bajulus (L.)]
1978 - IRG/WP 2120
The toxic values of 12 organic tin compounds towards newly hatched larvae of Hylotrupes bajulus were determined after 4- and 12-week test periods in comparison with bis-tri-n-butyltin oxide (TBTO). Tri-n-butyltin benzoate as well as the 2-, 3- and 4-methyl benzoate of tributyltin oxide were equally effective as TBTO and the latter two were somewhat more effective after a 12-week test period. Almos...
G Becker
Kinetics and mechanism of fixation of Cu-Cr-As wood preservatives. Part 6: The length of the primary precipitation period
1975 - IRG/WP 359
The end of the primary precipitation fixation period of CCA preservatives coincides with the first peak in pH versus time. This offers a simple way of estimating the duration of the period. The duration is determined by a number of factors and their interactions, the most important of which are: wood species (anatomy, natural pH, accessibility of reducing agents), preservative type, preservative c...
S-E Dahlgren
Influence of variable lignin content amongst hardwoods on soft-rot susceptibility and performance of CCA preservative
1982 - IRG/WP 1151
This paper presents the outline of an argument, based on both new and established data, which relates varying lignin content to variation of soft-rot susceptibility between hardwood species and of performance of CCA preservatives in controlling soft-rot. Although more data need to be generated to prove this relationship, sufficient evidence exists for the hypothesis to be given close attention, pa...
J A Butcher, T Nilsson
Sterilization to limit pretreatment decay: Internal temperature during kiln drying of Douglas-fir poles
2001 - IRG/WP 01-40206
Sterilization to limit pretreatment decay: Internal temperature during kiln drying of Douglas-fir poles. Fungal colonization of poles following peeling has been the subject of considerable concern among electric utilities. While the presence of fungi does not, in itself constitute a risk, the survival of these fungi through the conventional treating processes could allow them to continue to degrad...
J J Morrell, P G Forsyth, K L Levien
Co-operative tests concerning influence of solvent and drying method on the toxic limit of wood preservatives against Basidiomycetes. Preliminary report
1971 - IRG/WP 204
In the Working Group II of the Organization for Economic Co-operation and Development working group on wood preservation (now International Research Group on wood preservation) it was agreed that more knowledge was necessary concerning the influence of the solvent on the toxic limit of organic solvent types of wood preservatives against Basidiomycetes. A test program was drawn up and after discuss...
T Hof
Effect of post-treatment processing on leachability of ACZA-treated douglas-fir lumber
1998 - IRG/WP 98-50109
The effect of post-treatment procedures that more rapidly precipitate copper, zinc, and arsenic in douglas-fir treated with ammoniacal copper zinc arsenate (ACZA) on subsequent leaching resistance were investigated at two retentions (6.4 and 40 kg/m3). Total leaching was greater from boards treated to the higher retention. At both levels, copper was lost at the highest rate. Post-treatment process...
J J Morrell, C S Love, S Kumar, C M Freitag
Co-operative tests concerning the influence of solvent and drying method on the toxic limit of wood preservatives against Coniophora cerebella
1972 - IRG/WP 216
In the working group II of the IRG it was agreed that more knowledge was necessary concerning the influence of the solvent on the toxic limit of organic solvent types of wood preservatives against Basidiomycetes. A test program was drawn up and after discussion in the mentioned working group the final program was accepted by the co-operating institutes in 1969. In the test program two fungicides, ...
T Hof
Effect of wood decay on the proportional limit of thin wood samples stressed in the bending mode
2006 - IRG/WP 06-20334
When using bending stiffness as a measure of wood decay it is advantageous to repeatedly test individual samples after they are exposed to decay fungi for varying periods of time. In order to obtain reliable results, variation in modulus of elasticity (MOE) values of the test samples that are repeatable bent to a given deflection must be considered. In this study it was shown that sound 3mm thick ...
G Li, D Nicholas, T Schultz
Modelling of onset of mould growth for wood exposed to varying climate conditions
2009 - IRG/WP 09-20414
A performance-based service life design format based on climatic exposure on one hand and “resistance” of wood against mould growth on the other hand, is presented in this paper. A limit state for onset of mould growth is defined as the occurrence of traces of mould observed by microscopy. A dose-response model is proposed by which onset of mould growth can be predicted for an arbitrary climat...
S Thelandersson, T Isaksson, A Ekstrand-Tobin, P Johansson
Decay hazard mapping for Europe
2011 - IRG/WP 11-20463
In this study, two different dose-response models for above-ground decay as well as a model transferring macro climate data to wood climate data are presented. The models base on data from field trials, which had been conducted at 28 European test sites, and were used to calculate the relative risk for decay caused by climate variability in Europe. The two dose-response models give coherent result...
C Brischke, E Frühwald Hansson, D Kavurmaci, S Thelandersson
Quantitative design guideline for wood outdoors above ground applications
2011 - IRG/WP 11-20465
This paper describes the background and principles behind an engineering design guideline for wood in outdoor above ground applications, i.e. use class 3 according to EN 335. The guideline has been developed in the European research project WoodExter and can be seen as a first prototype for a quantitative design tool in the area of wood durability. It is based on a defined limit state for onset of...
S Thelandersson, T Isaksson, E Suttie, E Frühwald, T Toratti, G Grüll, H Viitanen, J Jermer
Service life evaluation of wood - an engineering approach
2013 - IRG/WP 13-20515
A performance-based service life design format based on climatic exposure on one hand and “biological wood resistance” on the other hand is presented in this paper. Important concepts are the introduction of limit states as well as reliable performance models for the biological processes, by which onset of deterioration can be predicted for arbitrary climate histories. Examples of applications...
S Thelandersson
Protein extraction from wood decay fungus Postia placenta
2014 - IRG/WP 14-10827
Wood decay fungi (often distinguished as white rot and brown rot) belonging to the basidiomycetes, are common inhabitants of forest litter, where they play an important role in carbon cycling. Brown rot fungi are perhaps the most important organism involved in the degradation of wood products, and of considerable economic importance. Brown rotted wood loses strength very early because of the rapid...
A Pilgård, P Arnold, K Richter
Mineralization of European oak with various ionic salt solutions to achieve an in situ precipitation of calcium oxalate
2019 - IRG/WP 19-40861
Thin specimens of European oak (Quercus spp.) with the dimensions of 4 × 20 × 50 mm3 were treated with various aqueous ionic salt solutions of calcium chloride, potassium oxalate and calcium acetate. Additionally, the oak was treated with combinations of calcium chloride and potassium oxalate, as well as calcium acetate and potassium oxalate with the aim to precipitate in situ the water insolubl...
T Franke, T S Volkmer
Influence of weathering of wood surfaces before and after treatment with iron(II) sulphate
2023 - IRG/WP 23-30786
Outdoor wood is exposed to various factors that cause the wood to grey or age. The ageing processes can vary greatly depending on the exposure. Parts of the wood that are not exposed to external factors, e.g. under the eaves, are less exposed and the ageing process is therefore slower. This can be accelerated by solutions based on iron ions. In this way, the wood greys quickly and evenly. However,...
B Lesar, M Humar, F Osvald