Your search resulted in 174 documents. Displaying 25 entries per page.
Tests with ammoniacal copper and alkyl ammonium compounds as wood preservatives
1984 - IRG/WP 3299
Formulations based on copper and alkyl ammonium compounds in ammonia solution have been tested in a fungus cellar on Pinus radiata and Fagus sylvatica. This type of products gives promising results as wood preservatives, especially on hardwood and are safe to destroy by e.g. combustion. The best results were achieved with a dialkyl ammonium compound, Cu/octyldecyl dimethyl ammonium chloride (NH3)....
C-E Sundman
Soluble nutrient influences on toxicity and permanence of CCA preservatives in wood
1980 - IRG/WP 3144
The influence of soluble carbohydrate and nitrogenous components concentrated at evaporative surfaces of wood on the toxicity and permanence of CCA preservatives has been examined using soil-burial techniques. Nutrient concentrations in lime (Tilia vulgaris Hayne) have been shown to be associated with reduction of toxic limits of preservatives to an extent in which a 100% increase in preservative ...
B King, G M Smith, A Bruce
Comparison of methods for monitoring CCA fixation
1994 - IRG/WP 94-40023
The CCA fixation status in the outer 12.5 mm of pole sections of southern pine (Pinus sp.), red pine (Pinus resinosa) and lodgepole pine (Pinus contorta var. latifolia) were followed during fixation at 21°C under non-drying conditions by the following procedures: - Qualitative CrVI indication by the chromotropic acid spot test. - Quantitative CrVI in the expressate by the diphenylcarbazide method...
P A Cooper, Y T Ung, G Zanjani
A laboratory study on effect of coating materials on leaching of copper from CCA treated wood
2001 - IRG/WP 01-50176
Components of CCA preservatives can leach into surrounding soil and water and have some effect on germination and growth of some plants. In this report, the effect of coating materials in reducing chemical concentration in the leachate were evaluated. Rubber wood blocks (Hevea brasiliensis) treated with CCA were fixed at room temperature at high humidity. After air dried, they were painted with co...
A Veenin, T Veenin
Rainfall simulation to assess CCA permanence
1991 - IRG/WP 2373
During experimental work on accelerated fixation of chromium containing preservatives a method has been developed which compares the degree of preservative levels of contamination of simulated preservative fixation in timber with the levels of simulated rainfall. This method uses commercial sized wood sections wetted in a way that simulates actual rainfall and relates the associated run-off contam...
P Warburton, J A Cornfield
The effect of composition on the effectiveness and fixation of CCA and copper/chrome preservatives. Part 1: Effectiveness. Part 2: Selective absorption and fixation
1973 - IRG/WP 324
A preliminary study of a wide range of copper-chrome-arsenic formulations indicates that the most effective are in the region, CuSO4 · 5H2O - 35 to 45 per cent; K2Cr2O7 - 40 per cent and above; As2O5 · 2H2O - 25 to 15 per cent or less. Effectiveness appears to depend more on the copper content than the copper - arsenic. Observations on selective absorption and leaching suggest that the chromium ...
D N R Smith, A I Williams
The relationship between the electrical resistance and fixation of water-borne CCA salts and pressure-treated wood
1991 - IRG/WP 3657
Two investigations at 22°C and 30°C have been carried out. The electrical resistance in the treated wood and chemical analyses of the remaining amount of unfixed copper, chromium and arsenic were investigated. Samples impregnated with water were used as references. To hold the samples moist during the investigation, each sample was wrapped in a polyethylene plastic foil immediately after impregn...
F G Evans, B Nossen
Leachability of didecyldimethylammonium chloride (a quaternary ammonium compound) from four wood species
1982 - IRG/WP 3204
Sapwood blocks prepared from red pine, ponderosa pine, southern yellow pine and hem-fir (a commercial mixture of western hemlock and amabilis fir) were treated with didecyldimethylammonium chloride, (an alkylammonium compound, AAC). After oven drying the blocks were vacuum impregnated with distilled water and subjected to a static leach cycle for 48 hours. The leachate was analyzed and the amount ...
J N R Ruddick, A R H Sam
Effect of water repellents on leaching of CCA from treated fence and deck units - An update
1997 - IRG/WP 97-50086
In an earlier study, it was shown that CCA leaching losses could be reduced over an accelerated leaching and short term natural weathering exposures by post treatment application of a commercial water repellent. In this report, the effects of this coating and two commercial CCA solution water repellent additives are evaluated after two years of natural weathering. Wood boards were pressure treated...
P A Cooper, Y T Ung, R M Vicar
Susceptibility of CCA treated North American hardwoods to Chaetomium globosum decay
1998 - IRG/WP 98-10278
Seven species of hardwood, Beech (Fagus grandifolia), Basswood (Tilia americana), Maple (Acer rubrum), Oak (Quercus rubra), Trembling Aspen (Populus tremuloides), White birch (Betula papyrifera) and Yellow poplar (Liriodendron tulipifera) were vacuum or pressure impregnated with CCA, at four retention levels. The CCA was allowed to fix in the wood at 35°C. Red pine (Pinus resinosa) was also inclu...
U Srinivasan, Y T Ung, P A Cooper
Waterborne preservative treatability of tamarack (Larix laricina (Du Roi) K.Koch)
1998 - IRG/WP 98-40112
Eastern larch or tamarack (Larix laricina (Du Roi) K.Koch) lumber from New Brunswick, Canada was evaluated for preservative treatability with chromated copper arsenate (CCA-C) and ammoniacal copper arsenate (ACA). The fixation and leaching characteristics of CCA-C treated tamarack sapwood and heartwood were also evaluated. CCA-C penetration into both sapwood and heartwood was poor. ACA fully penet...
A Taylor, Y T Ung, P A Cooper
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
Chromium in wood preservation: Health and environmental aspects
1978 - IRG/WP 3120
The majority of water-borne salts in current use contain hexavalent chromium, usually as dichromate or chromium trioxide. In about 1913 it was suggested that chromates, phosphates or borates could be added to the sodium fluoride and dinitrophenol mixtures then in use in order to inhibit corrosion. Dichromates were found to be most suitable and the resulting mixture known as Thriolith and later Tri...
T R G Cox, B A Richardson
Heat transfer and wood moisture effects in moderate temperature fixation of CCA treated wood
1994 - IRG/WP 94-40022
Practical aspects of heat transfer and fixation of wood exposed to drying conditions after CCA treatment are considered. The rates of heat transfer and CCA fixation are substantially influenced by the cooling effect of water evaporating from the wood surface when drying occurs during fixation. At least in the early stages of fixation, the wood temperature approaches the wet bulb temperature, rathe...
J Chen, M Kaldas, Y T Ung, P A Cooper
Difference of CCA efficacy among coniferous wood species
1990 - IRG/WP 3601
Wood blocks of Cryptomeria japonica, Tsuga heterophylla, and Pinus radiata successively extracted with n-hexane, ether, and methanol were treated with various concentrations of CCA type 3, which were subjected to the decay by Tyromyces palustris. The weight loss were different among species and kinds of extraction. Cryptomeria japonica treated with CCA had higher fungal resistance than Tsuga heter...
K Yamamoto, M Inoue
Fundamentals on steam fixation of chromated wood preservatives
1988 - IRG/WP 3483
Weathering of treated wood directly after impregnation leaches up to 2% of copper-chromate-containing wood preservatives. Almost total fixation of Cr+6 is achieved by steaming the treated wood at 100°C to 120°C, preferably 110°C. To initiate such spontaneous fixation 85°C to 90°C inside the wood are essential, which requires heating times ranging from 20 to 80 min, depending on timber species...
R-D Peek, H Willeitner
Leachabilty and efficacy of fatty acid derived boron esters as wood preservatives - leachability and efficacy of fatty acid derived boron esters as wood preservatives
2004 - IRG/WP 04-30351
Borates have many advantages as wood preservatives. However, boron is susceptible to depletion under humid conditions and this restricts its outdoor use. In order to reduce boron leachability in treated wood, one of the anticipative approaches is to use organic fixed boron-based preservatives. This study investigated the leachability of six boron ester compounds as potential preservatives. Scots p...
A Mohareb, J Van Acker, M Stevens
Changes in fat and moisture contents, and nitrogen fixation in laboratory maintained termites
1984 - IRG/WP 1242
Orphaned groups of termites of Coptotermes acinaciformis and Mastotermes darwiniensis were maintained in the laboratory for several months on two dietary regimes, and changes in their fat contents, moisture contents and nitrogen fixation rates were examined. There were no significant feed or feed time effects for either species. For Coptotermes acinaciformis, there was a highly significant time ef...
J R J French, P J Robinson, L G Turner, P J Pahl
Dimensional stabilization and decay resistance of wood treated with brown-rotted lignin and copper sulfate
1990 - IRG/WP 3608
The objective of this study was to evaluate the potential usefulness of brown-rotted lignin (BRL) as a dimensional stabilization and copper complexing agent for wood treatment. For dimensional stabilization, aqueous solutions of the lignin extract were combined with either copper sulfate, glyoxal or other additives. Anti-shrink efficiency (ASE) values as high as 42% were obtained with wood treated...
L Jin, D D Nicholas, T Schultz
Laboratory Evaluation and Field Trial of Chlorothalonil and Copper-based Preservatives and Leaching Performance of Copper in Copper Treated Wood
2002 - IRG/WP 02-30279
Soil block test and field trial of some Chinese plantation wood species pine and poplar treated with chlorothalonil formulations and copper-based preservatives such as ACQ-B and copper citrate (CC) were conducted. The results of soil block test indicated that chlorothalonil formulations and ACQ-B as well as CC are very effective for controlling the 2 fungi species Corious versicolor and Poria plac...
Mingliang Jiang, Ping Wang, Chungen Piao, Zhaobang Li, Quan Lu, Lei Liu
Utilization of coconut timber from north Sulawesi, Indonesia. Part 2: Treatability
1994 - IRG/WP 94-40025
Under tropical conditions coconut wood is quickly degraded by mold and blue stain fungi. Low density wood in ground contact is commonly decomposed by wood destroying fungi within a period of only a few months, higher density wood from the outer stem regions within 24 to 30 months (MOSTEIRO, CASIN, SERIBAN 1976; McQUIRE 1975). Moreover, according to McQUIRE (1975) green wood of lower density is hig...
R-D Peek
Fixation of CCA preservatives in cocos-, oil- and rattan-palm
1986 - IRG/WP 3371
In previous tests with jubaea-palm almost no fixation of a CCA-preservative Type B could be achieved, consequently, further leaching tests were carried out with samples of 1 cocos-, 1 oil- and 2 rattan-palms from Malaysia. A good fixation of chromium and copper took place in cocos-palm after 4 weeks storage at 28°C. Nevertheless the fixation was slower than in pine-wood and demanded an elevated t...
H Willeitner, K Brandt
Oxidation of wood components during CCA-C fixation
1993 - IRG/WP 93-30024
Pre-extracted radial sections of southern yellow pine sapwood were treated with CCA-C and analyzed by X-ray photoelectron spectroscopy (XPS). The ratio of C1 (carbon bonded to carbon and/or hydrogen) to C2 (carbon bonded to one oxygen) in XPS Cls spectra was taken as a measure of the progress of oxidation of wood components during CCA fixation. This ratio was 0.82 before CCA treatment and increase...
M Kaldas, P A Cooper
Rapid fixation of Chromated Copper Arsenate (CCA) wood preservatives by microwave treatment
2000 - IRG/WP 00-40184
Rapid microwave heating of freshly chromated copper arsenate (CCA) treated timber indicates that rapid preservative fixation is possible within approximately 40 seconds. The leaching of CCA was evaluated using simulated rainfall. Cost analyses indicates that microwave fixation using an on-line conveyor belt fixation process with an output of 4m3/hour using a microwave power supply of 230 kW costs ...
G Torgovnikov, P Vinden, E Mapanda, P R S Cobham
Microwave treatment to Accelerated fixation of copper-ethanolamine (Cu-EA) treated wood
2004 - IRG/WP 04-40271
This study evaluated the use of microwave post-treatment to accelerate fixation of copper-ethanolamine (Cu-EA) treated 19 mm southern yellow pine sapwood cubes. Cubes were pressure treated at 3.2 and 6.4 kg/m3 Cu retention target, after which they were microwave post treated during different duration periods. An accelerated AWPA leaching test was conducted during 300 hours to determine the amount...
Jinzhen Cao, D P Kamdem