Your search resulted in 1274 documents. Displaying 25 entries per page.
Preliminary PIXE micro-analysis of copper-chrome-arsenic preservative treated Malaysian hardwoods
1999 - IRG/WP 99-20169
The novel nuclear microscopy, essentially the Particle-induced X-ray Emission (PIXE) system, was applied for examining the macro-distribution and micro-analysis of copper-chrome-arsenic (CCA) preservative in Malaysian hardwoods Koompassia malaccensis, K. excelsa, Alstonia spp. and Dipterocarpus spp., and one temperate pinewood Pinus sylvestris, where the preservative retention differed between the...
A H H Wong, R B Pearce, G W Grime, F Watt
Effect of climate, species, preservative concentration and water repellent on leaching from CCA-treated lumber exposed above ground
2001 - IRG/WP 01-50178
Few studies have examined leaching of chromated copper arsenate (CCA) from treated wood in above ground exposures due to the assumption that leaching is less severe compared to wood in continuous contact with soil or water. However, a significant portion of CCA treated wood is used for above ground applications, exposing considerable volumes of the preservative to precipitation and potential leach...
J L Taylor, 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
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
Observations on preservative penetration in poplar
1991 - IRG/WP 3662
In the course of studies on the CCA treatment and durability of poplar timber a zone of refractory wood at the sapwood/heartwood boundary was observed. Further studies were conducted to investigate the causes of this refractory behaviour. The initial results have suggested that the presence of lipid storage products in the ray tissue may lead to impermeability, either by directly blocking pits or ...
R J Murphy, S U Din, M J Stone
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
Standardization of preservative treated timber species for conductor, insulator and transformer packing of REB
1996 - IRG/WP 96-40071
In order to resolve the post landing failure problem of wooden packing for conductor, insulator, transformer of REB, the names of the suitable timber species from different parts of the world, irrespective of countries of origin have been standardized along with their strength and treatability grades. The CCA treatability of some Pakistani timber species have been presented for example which was t...
A K Lahiry
Leaching of preservative components from pine decking treated with CCA and copper azole, and interactions of leachates with soils
2001 - IRG/WP 01-50171
Radiata pine decking was treated with CCA and copper azole preservatives to Australian H3 retention using conventional and modified Bethel schedules, and air-dried. Treated decking boards and durable hardwood controls were subjected to leaching in weather-exposed decks, and matching 19mm cubes were leached in extended AWPA E11-97 lab tests. Deck runoff and E11 leachate water was analysed after rai...
M J Kennedy, P A Collins
Interactions between water-borne preservatives and emulsion additives that influence the water repellency of wood
1991 - IRG/WP 2374
Incorporation of non-polar additives into water-borne treatments through of emulsion technology can greatly improve the physical characteristics of wood in service. Of specific interest with these emulsions is their effectiveness in reducing the rate of wood swelling. We have observed that the presence or absence of preservatives can often significantly influence the resultant effectiveness of the...
A R Zahora
A bioassay to determine preservative retention in hardwoods and southern pines
1982 - IRG/WP 2183
In this paper the author discusses and suggests a new method of evaluating preservative retention in treated woods by means of bioassays. Twelve North American species were tested with different retention levels of pentachlorophenol (PCP) and copper/chrome/arsenic (CCA) preservatives. The results observed in this work show that among other fungi, Aspergillus niger responds to both preservatives, w...
J C Moreschi
Adequate preservative treatment of kiln dried Eucalyptus camaldulensis and Acacia mangium for tropical and subtropical wood poles
1996 - IRG/WP 96-40075
The Eucalyptus camaldulensis and Acacia mangium round timbers kiln-dried at EMC and full cell pressure treated with CCA-C ensured requisite penetration and adequate dry retention (30 kg/m³ or 4% w/w). The sufficient inherent strength, seasoning property, treatability of sapwood and heartwood equivalent to 44% of radius, natural durability of heartwood, and field investigation on service performan...
A K Lahiry
An observation of seasoning, preservative treatment and storing of CCA treated 30 bangladeshi hardwood species for crossarms
1995 - IRG/WP 95-40058
Observed kiln seasoning, preservative pressure treatment and storing of CCA treated 30 Bangladeshi hardwood species for crossarms. It revealed that it was very difficult to kiln season and preservative pressure treatment of thirty species together in a single charge and found that when species of different specific gravity kiln season together there occur some objectionable seasoning degrades, and...
G N M Ilias, M D Rokib-ul-Hafiz
A comparison between high and conventional incision densities for improving preservative treatment of Douglas-fir heartwood lumber
1993 - IRG/WP 93-40009
Incising is required for the preservative treatment of most wood species from the western United States; however, there is considerable debate about the density of incisions required to achieve adequate treatment. Previous studies have shown that the incision effect on treatment is relatively narrow, suggesting that incision densities should be significantly increased over current practices and st...
S T Lebow, J J Morrell
Diffusion modeling of inorganic wood preservative leaching in service
2005 - IRG/WP 05-50224-5
To evaluate the potential environmental and health implications of leaching of inorganic wood preservatives in service under different conditions, there is a need for a predictive model that provides estimates of the rate and extent of leaching over a wide range of product dimensions and exposure conditions. In this paper, we show that the leaching behavior of inorganic preservative components fr...
L Waldron, P A Cooper, Y T Ung
Biological Safety Evaluation of Animal Contact of Preservative-Treated Wood
2003 - IRG/WP 03-50196
Biological safety of preservative-treated woods that could be contacted to human and animal was evaluated for rat and rabbit exposed to CCA-, ACQ- and CCFZ-treated woods. The accumulation of preservatives ingredient in the rat’s plasma and viscera, and the transforming function of replacing preservatives were examined in this study. The result indicated that preservative-treated wood did not bri...
Dong-heub Lee, Dong-won Son, Myung Jae Lee, Chang Ho Kang, Cheon Ho Kim, Eui-Bai Jeung
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
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
Leaching of arsenic, copper and chrome from preservative-treated timber in playground equipment
1984 - IRG/WP 3149
Samples were taken from CCA-treated timber in sand play boxes and other play ground equipment. Sand was also sampled. Sand and wood samples were analysed for copper, chrome and arsenic by AAS. About 20-25% of the arsenic had leached from the timber after 2-4 year's exposure in the playgrounds. Very little of the copper and chrome had been leached. Sand collected in the close vicinity of t...
B Henningsson, B Carlsson
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
The efficacy of polymer/preservative treatments in soil-bed exposure
1992 - IRG/WP 92-3729
Southern pine was treated with CCA, CCB, sodium borax/boric acid, or disodiumoctaborate, alone or in combination with an acrylic polymer system containing a water repellent. Treated samples were subjected to an unsterile soil burial test. The addition of polymer reduced the weight loss in borontreated samples at the lower retentions but not at the higher retention. Results with borates indicate th...
R J Murphy, H M Barnes, S M Gray
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
Some practical implications from recent research on the fixation of CCA preservatives
1975 - IRG/WP 358
The mechanism of fixation of CCA preservatives is briefly described. If the temperature is increased during the primary fixation period, the formation of intermediate fixation compounds is less extensive. The length of the primary fixation period is of practical interest. It is determined by preservative composition and concentration, temperature and wood species. Diagrams are given for Pinus sylv...
S-E Dahlgren
Moderate temperature fixation of CCA-C
1989 - IRG/WP 3522
Several Canadian treating plants are using moderate temperature (40-60C°) fixation chambers to reduce drippage and leaching from fresh CCA treated wood. In this study, chromium reduction and surface leaching properties of CCA-C treated red pine (Pinus resinosa) pole sections were monitored during exposure to temperatures of 50-60C° and 90-100% RH conditions. Chromium-VI concentration in the abso...
P A Cooper, Y T Ung