Your search resulted in 375 documents. Displaying 25 entries per page.
Five years field test results for CCA and ACQ preservatives fixed in different climates
1999 - IRG/WP 99-30208
During assessment of the ground contact stakes in the Norwegian test field, we have found that very often the first visual rot attack is in the zone of the stakes were the stakes have been in contact with each other during the fixation. These parts are usually light green, caused by the lack of light during fixation, compared to the rest of the stake surface, which has a darker colour. To investig...
F G Evans
Investigation of temperature effect on fixation of Celcure preservative (ACC) in Hornbeam (Carpinus betulus I)
2003 - IRG/WP 03-30304
In this research, the fixation speed of Celcure 2 % (ACC) preservative salt, under temperature of 30 ºC, 40 ºC and 50 ºC on intact wood specimens of hornbeam was investigated. For this purpose, blocks of wood with 2Í 2 Í2 cm dimensions of hornbeam were prepared and saturated with 2% ACC concentration by full-cell process. The specimens were put in three incubators at the above-mentioned temperatures. For measuring the percentage of fixation through time, the specimens were extracted by using hydraulic pressure equipment, under 70 Mpa pressure. The PH of extraction was measured with the method of Diphenyl Carbazid and by using spectrophotometer. This measurement was done continuously and the amount of 6-valence chromium concentration present in the extract was compared with the amount of chromium concentration in the primary solution and then the percentage of fixation was calculated.
The results showed that the decrease in 6-valence chromium is accompanied with increase of PH, this due to absorption of positive hydrogen ion by 6-valence chromium for reduction to 3-valence chromium and also ion –exchange of active components with wood during the primary phase of fixation. Also, the time necessary for reaching complete fixation in intact wood in the fixation temperature conditions of 30, 40, 50 ºC were 98, 52, 24 hours, respectively. In general, the results showed that temperature has effective role accelerating of fixation process.
R Imani, R E Majdar, A Karimi
Treatment of wood by diffusion of salts
1976 - IRG/WP 368
A brief survey is given on the treatment of wood by diffusion of salts. The compounds used for this process, mainly boron and fluorine compounds, are mentioned and the factors influencing diffusion described. The main pre-condition is a high moisture content of the wood of above 40%. Fields of application are fresh roundwood, remedial treatment of poles and sleepers, preservation of posts and espe...
G Becker
Soft rot test of copper/chrome/arsenic treated heartwood of three Malaysian timbers by the vermiculite-burial method. (+ correction document of 25 July 1990)
1990 - IRG/WP 2354
Heartwood of copper-chrome-arsenic (CCA) treated kempas (Koompassia malaccensis), tualang (Koompassia excelsa) and keruing (Dipterocarpus spec.) was found to be susceptible to soft rot in recent pole surveys. Standardized heartwood blocks were impregnated with 0 to 6.3% (w/v) CCA and challenged to decay for twelve weeks by a mixed inocula of Chaetomium globosum, Glenospora graphii, Humicula grisea...
R-D Peek, A H H Wong
Distribution of boron from fused borate rods in Douglas-fir transmission poles
1996 - IRG/WP 96-30112
The diffusion of boron from fused borate rods (disodium octaborate tetrachydrate) was monitored over 42 months in CCA-treated Douglas-fir transmission poles. The boric acid equivalent was estimated by the curcumin/salicylic acid color test on increment cores removed from the poles. Moisture content of the poles was quite variable but was always above 20 percent. The percent of increment core lengt...
T L Highley, F Green III, W F Finney
Multiple-Phase Pressure (MPP) Process: One-stage CCA treatment and accelerated fixation process. 4. MPP compared with other processes for achieving acceptable treatment of radiata pine heartwood
1998 - IRG/WP 98-40115
Although radiata pine sapwood is very amenable to preservative treatment, it is often difficult to achieve the required standard for heartwood treatment.
A preliminary investigation showed that to achieve the NZ Timber Preservation Council minimum penetration requirements for radiata pine heartwood using the Multiple-Phase Pressure (MPP) Process, a hydraulic pressure of at least 1250 kPa for 20 m...
K Nasheri, J A Drysdale, G Durbin, M E Hedley
Thickened boron treatment
1990 - IRG/WP 3632
Commercial trials with thickened boron preservatives "Diffusol™" indicate a number of advantages when compared to traditional methods of dip-boron preservative treatment. These include: (i) more even uptake and distribution of preservative on and within the timber; (ii) faster diffusion times; (iii) the treatment of gauged timber (though improved retention); (iv) saving in energy costs (heating ...
P Vinden, J A Drysdale, M Spence
The development of a new boron-based wood preservative
1995 - IRG/WP 95-30085
The paper describes a new boron based wood preservative for the treatment of green timber. The product offers many benefits over conventional boron diffusion treatment including: 1. high viscosity, high concentration formulation; 2. permits dip treatment of a wide range of sawn board and pole sizes at ambient temperatures; 3. permits full cross section diffusion of borates without block stacking a...
P Turner, D Conradie
Treatment of wood with boron esters
1995 - IRG/WP 95-30087
The treatment of wood and wood products with boron esters is reviewed. The physical and chemical characteristics of boron esters affecting the treatability of wood are discussed, in particular thermal decomposition and rates of hydrolysis. The uses and methods applying boron esters as wood preservatives include: (i) Solutions of boron esters for remedial and diffusible treatment of wood; (ii) soli...
J Romero, P Vinden, J A Drysdale
Gaseous preservative treatment of wood
1990 - IRG/WP 3631
A recent development in processing wood with a gaseous preservative means that dry, treated wood can be produced in under 30 hours with the benefits of product diversification, faster stock turnover and the ability to respond to short term demand. About 400,000 m³ of wood are treated each year in New Zealand with boron salts to protect from borer infestation. Traditionally this treatment is effec...
R Burton, A J Bergervoet, K Nasheri, P Vinden, D R Page
Differential retention and leaching of CCA (C) in sapwood and heartwood of Kenyan-grown blue gum (Eucalyptus saligna) and black wattle (Acacia mearnsii)
2005 - IRG/WP 05-30371
Retention and leaching of CCA(C) in small samples of sapwood and heartwood of Kenyan-grown blue gum (Eucalyptus saligna) and black wattle (Acacia mearnsii) were tested under laboratory conditions. Clear samples (100mm x 30mm x 40mm) were removed from the sapwood and heartwood of sampled defect-free and sound plantation trees of the two species. These were separately air-dried to 15% MC, end-seal...
R Venkatasamy
Chemically modified tannin and tannin-copper complexes as preservatives for wood
2001 - IRG/WP 01-30271
The efficacy of Mimosa tannin, chemically modified tannin, and tannin-copper complexes as wood preservatives was studied. When the tannin-ammonia-CuCl2 solutions were impregnated into wood specimens in a one-step procedure, a large quantity of the tannin-copper complex was fixed in the specimens. Little of the complex was leached from specimens by a weathering treatment, and these specimens showed...
H Yamaguchi
Copper based wood preservative - A new approach using fixation with resin acids of rosin
2000 - IRG/WP 00-30249
Copper soaps with carboxylic acid groups of resin acids of rosin were shown to be potential long-term wood preservatives. The principle involved is the attachment of copper to the network formed by the inorganic part of the preservative (rosin) through the -COOH groups. The mechanisms of fixation have been studied, and it has been shown that this association could be obtained : (1) by forming the ...
C Roussel, J P Haluk, A Pizzi, M-F Thévenon
A spectroscopic investigation of copper ethylenediamine fixation in wood
1999 - IRG/WP 99-20160
The fixation reaction which take place between copper ethylenediamine (Cu-en) solution and wood were expolored using X-ray photoelectron spectroscopy (XPS) and Fourier Transformed Infrared Spectroscopy (FTIR). The FTIR spectra revealed that copper reacts with the carboxylic acid and phenolic groups in wood to form stable complexes. The copper ethylenediamine complexes formed in wood were identifie...
Xiao Jiang, J N R Ruddick
A technique for determining the efficacy of water diffusible preservative plugs for implanting in joinery in service
1987 - IRG/WP 2291
A technique is described for determining the efficacy of soluble, diffusible preservative plugs for eradicating decay in joinery. It uses blocks of Scots pine sapwood or heartwood adjusted to known moisture contents prior to the establishment of the test fungus Coniophora puteana, from a single longitudinal dowel and the subsequent introduction of the preservative plugs. Prevention of decay, eradi...
J K Carey, A F Bravery
Termite resistance of treated wood in an above-ground field test
1985 - IRG/WP 2241
A field test method has been developed for evaluating the susceptibility of wood products to termites in protected situations above ground. In this method fungal attack on the wood products is minimal, though decay has been observed in conjunction with termite attack in some specimens. Preliminary results from exposure of replicate wood samples treated with preservatives in Florida to Reticuliterm...
A F Preston, P A McKaig, P J Walcheski
The fixation of copper in Pinus sylvestris using the sodium salts of two polyhydroxycarboxylic acids
1992 - IRG/WP 92-3706
As part of the research concerned with the development of fixed, copper based preservatives, the salts of polyhydroxycarboxyIic acids, have been used in copper sequestration studies and fixation trials in Pinus sylvestris splinters. Selected compounds have been shown to be effective sequestrants at low concentrations allowing alkaline solutions to be formulated. Leaching trials following a 48 hour...
M Bacon, J A Cornfield
Effect of leaching temperature and water acidity on the loss of metal elements from CCA treated timber in aquatic applications. Part 1: Laboratory scale investigation
1995 - IRG/WP 95-50046
In order to investigate the applicability of current prestandard leaching test methods, a series of experiments has been performed on CCA impregnated wood dealing with the influence of pH, temperature and agitation of the surrounding water. The leaching method used in this first part of the investigation is the European prestandard drafted by CEN/TC38/WG11, a short term dynamic leaching test under...
G M F Van Eetvelde, R J Orsler, G E Holland, M Stevens
Examination of preservative-treated Pinus sylvestris using electron paramagnetic resonance
1992 - IRG/WP 92-3710
EPR is currently being used to help elucidate the nature and extent of the chemical reactions occurring between wood and copper based timber preservatives. In the work reported here treated Scots pine samples were examined at room temperature and in the frozen state. Plots of the electronic parameters A|| vs. g|| were found to be a useful index of the electronic properties of the various formulati...
A S Hughes, R J Murphy, J F Gibson, A J Cornfield
The influence of timber species and preservative treatment on spore germination of some wood-destroying Basidiomycetes
1988 - IRG/WP 2300
Basidiospores from six wood decay fungi exhibited varying germination rates on untreated softwood and hardwood blocks. Germination inhibition of all test fungi was recorded on pine sapwood. No preference for a certain timber species by a particular fungus was evident. Whereas almost complete inhibition of germination occurred on wood treated with a quarternary-ammonium based wood preservative, mos...
B M Hegarty, G Buchwald
Less pollution due to technical approaches on accelerated steam fixation of chromated wood preservatives
1988 - IRG/WP 3487
Steaming of freshly treated wood at 100°C to 120°C initiates a spontaneous fixation of copper-chromate-containing wood preservatives. For the performance, a suitable anticorrosive equipment is necessary. Good results can be achieved using a separate steaming equipment which allows a rapid heating of the wood. While warming-up, in the wood some preservative solution extends and can be partly extr...
H Willeitner, R-D Peek
Shorter-term biological control of wood decay in pre-seasoning pine roundwood as an alternative to chemical methods
1992 - IRG/WP 92-1555
Previous studies on the long-term control of decay in creosoted transmission poles, using Trichoderma and other antagonistic moulds, have met with limited success. However, it is possible biological control is more suited to control of decay on shorter time scales. An earlier study, focusing on pre-seasoning treatment of transmission poles showed that favourable porosity increases could be brought...
M W Schoeman, D J Dickinson
Influence of water soluble extractives on CCA fixation and leaching performance of red maple and red oak
1997 - IRG/WP 97-30133
We have observed several peculiarities in relation to CCA fixation in red maple and red oak woods such as high variability in fixation rates and leaching performance in maple and precipitate formation in solutions expressed from CCA treated red oak wood blocks at different stages of fixation. We have postulated that the extractives could be the factor of influence, as this has already been reporte...
T Stevanovic-Janezic, P A Cooper, Y T Ung
Preservative leaching from copper-chrome-arsenic treated timber: Towards an international standard for environmental monitoring
1996 - IRG/WP 96-50076
A review of standards and legislative requirements around the world relating to environmental contamination from copper-chrome-arsenic wood preservative indicates a plethora of methodologies for expressing and determining contamination levels. The imposition of arbitrary quarantine periods for treated timber, or special fixation processes, appear to be applied without a rational analysis of what l...
S Walley, P R S Cobham, P Vinden
Effects of pre-harvest girdling on selected properties of red pine, red maple and Eastern larch
1999 - IRG/WP 99-40137
Trees of three species - tamarack (Larix laricina), soft maple (Acer rubrum) and red pine (Pinus resinosa) - were girdled immediately below the crown,one to two years before felling. The wood from these trees was compared with wood taken from un-girdled control trees felled at the same. Sapwood and heartwood, from the controls, and from above and below the girdle of treated trees, were examined fo...
A Taylor, P A Cooper