Your search resulted in 221 documents. Displaying 25 entries per page.
The present status, characteristics and problems of wood based turning handicrafts industry in Bangladesh
2005 - IRG/WP 05-40298
Cottage industry is an important sector both socio-economically and environmentally, because such industries provide jobs and income, which restricts destruction of forest and increase of agri-land. Study on the present status, characteristics, and growth potential of wood based turning handicrafts industry in Bangladesh revealed that in Khulna District, there are 20 (twenty) numbers of turning wo...
A K M A Bosunia, M A Islam, M M Rahman, A K Lahiry
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
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
Characteristics of thermally modified wood in vacuum
2004 - IRG/WP 04-40287
In commercial thermal wood modification processes nitrogen, steam or oil has been used for the reduction of oxygen content in the reactor atmosphere. In present study no special heating medium, but an initial vacuuming step has been used for this purpose. Mass loss, resistance to fungal decay, dimensional stability, bending strength and modulus of elasticity of heat treated wood were evaluated and...
G Rep, F Pohleven, B Bucar
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
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
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
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
Leaching Characteristics of Alder Wood Treated with Copper Based Wood Preservatives
2005 - IRG/WP 05-50225
In this study, it was designed for determining leaching characteristics of CCA and alternatives wood preservatives. Alder wood blocks were treated with CCA (1 % and 2 %), ACQ-1900 (2 % and 3 %), ACQ-2200 (1 % and 2 %), Tanalith E 3491 (2 % and 2.8 %), Wolmanit CX-8 (% 1 and 2 %). Leaching studies were conducted according to AWPA E11-97. Copper analyses of leachate were determined Atomic absorption...
A Temiz, Ü C Yildiz, E D Gezer, S Yildiz, E Dizman
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
A substantively bonded water repellent treatment based on chromium carboxylates
1985 - IRG/WP 3344
Chromium carboxylates soluble in toluene have been synthesised and applied to Scots pine (Pinus sylvestris) sapwood. Without any further treatment, the compounds may be readily leached from wood surfaces with toluene. After a period of heating however, they become fixed to the cell wall, substantial amounts being resistant to leaching even under reflux conditions for several hours. Treatment of wo...
J K Wright, W B Banks, W J Eilbeck
Relating CCA fixation to leaching of CCA components from treated products
1995 - IRG/WP 95-50045
The relationship between chromium fixation in CCA-C treated wood, as determined by CrVI analysis of solution expressed from treated wood and the leaching of Cu, Cr, As and CrVI in a simulated rain test are evaluated for dimension lumber (2"x6") and pole sections. Leachate concentrations after 2 hour exposure to a misting spray (about 300 mm cumulative rainfall) decrease rapidly with increased degr...
P A Cooper, R MacVicar, Y T Ung
Creosote for wood preservation. (Reissued from earlier OECD draft)
1970 - IRG/WP III 1A
The literature on this subject is extensive and, to some extent, repetitive so that for pratical reference purposes it is essential that selective surveys and bibliographies be prepared. Many of these exist and, as an example, the reports issued by The Coal Tar Research Association (Numbers 0156, 0292 and 0396) may be quoted. The following bibliography, listing the more important sources of inform...
Anonymous
Kinetics and mechanism of fixation of Cu-Cr-As wood preservatives. Part 4: Conversion reactions during storage
1974 - IRG/WP 332
Precipitates simulating those produced in wood by preservative fixation reactions were prepared by the reduction of Boliden K 33 and Celcure AP solutions with hydrogen peroxide and hydrazine. The pH changes on aging at 20 and 50°C were studied and related to the chemistry of fixation previously described. Hydrolysis of copper arsenates may render arsenic acid temporarily water soluble pending pre...
S-E Dahlgren
Fixation of chromated wood preservatives through technical drying
1990 - IRG/WP 3623
Twin samples of sawn timber of Pinus sylvestris and Picea sp. were treated with copper-chromate-containing wood preservatives and subsequently kiln resp. air dried. After drying, the distribution of preservative and rate of fixation were determined. Drying of freshly treated wood in a condenser type kiln at temperatures of 60°C and 80°C and in a vacuum type kiln at 55°C with a pressure of about...
R-D Peek, H Klipp
Experimental variations in the distribution of CCA preservative in lignin and holocellulose as a function of treating conditions (temperature, concentration, pH, species, and time)
1984 - IRG/WP 3277
The exact distributions between lignin and holocellulose and retentions on wood of copper, chromium and arsenic as a function of various sets of conditions in a 3x3x4x2 factorial experiment in which combinations of three temperatures of treatment, three CCA solution concentrations, four pH's of the initial CCA solution and two timber species, namely Pinus radiata and Eucalyptus grandis, a...
A Pizzi, E Orovan, M Singmin, A Jansen, M C Vogel
Leachability of active ingredients from some CCA treated and creosoted poles in service. A progress report after 10 years testing
1990 - IRG/WP 3627
CCA K33 TYPE B treated or creosoted poles, 10 pieces of each treatment type, have been monitored from the treatment plant to an electricity line, which was build up in Southern Finland in 1978. Preservative retention was determined by taking borings at four different levels: 1.5 m from the top end, 1 m above ground line, ground line and 0.5 m below ground. Determinations were made before setting u...
A J Nurmi
Multiple-Phase Pressure (MPP) Process: One-stage CCA treatment and accelerated fixation process. 3. Effect of process variables on sapwood treatment and CCA fixation.
1998 - IRG/WP 98-40114
The Multiple-Phase Pressure (MPP) Process achieves treatment and fixation as combined process using hot CCA, within a 2-3 hour time-frame. Timber is treated to saturation with hot CCA using an empty cell process. During the pneumatic pressure phase, hot solution is held in the wood in an otherwise liquid-free treatment vessel until fixation is >95% complete.
This report details a factorial des...
H Pearson, K Nasheri, J A Drysdale, G Durbin, M E Hedley
Bioefficacy of Cunapsol® treated western cedar and southern yellow pine
1996 - IRG/WP 96-30120
Western red cedar and southern yellow pine sapwood were dip treated with a new formulation of waterborne copper naphthenate (Cunapsol®) which complies with VOC regulations. Cunapsol dip treated samples were oven dried at 50°C for 48 hours and then water leached for two weeks. Decay resistance and leachability of preservatives from dip treated specimens were evaluated according to AWPA (American ...
D P Kamdem, M H Freeman, T L Woods
Chromated copper arsenate preservative treatment of hardwoods. Part 1: CCA fixation performance of seven North american hardwoods
1997 - IRG/WP 97-30131
There has been an increased interest in utilisation of hardwoods from eastern North America for exterior applications which require protection with preservatives such as CCA. We have examined CCA fixation at two selected temperatures of seven common North American species: red maple (Acer rubrum L.,), white birch (Betula papyrifera ), yellow poplar (Liriodendron tulipifera L.), trembling aspen (Po...
T Stevanovic-Janezic, P A Cooper, Y T Ung