Your search resulted in 250 documents. Displaying 25 entries per page.
Practical consequences of the clarification of the chemical mechanism of CCA fixation to wood
1983 - IRG/WP 3220
Practical consequences derived from the chemical investigation of the mechanism of fixation of CCA to the wood constituents are discussed. Among these, formulas for the calculation of the time of hexavalent chrome fixation are presented. Furthermore, three parameters are shown to be important to the long-term effectiveness of CCA-treated timber: (i) the temperature of treatment, (ii) the initial p...
A Pizzi
Environmental situation on wood preservation industries in Bangladesh
2000 - IRG/WP 00-50148
The hazard that wood preservative chemicals pose to people and the environment is serious. The lack of information, legislation and awareness create an unfavorable situation on wood preservation industries. In this regard, three wood preservation industries have been visited to collect the information about pollution. It was observed that different steps have been taken to minimize the contaminati...
K Akhter
Applications of the shower test. Part B: Results from CC and CCB treated wood: influence of fixation process
1993 - IRG/WP 93-50010
This report outlines the results of shower tests conducted on CC and CCB treated wood. The results indicate the fairly good fixation of chromium and the reasonable fixation of copper in CC and CCB formulations, as judged by the leaching limits within the Environmental Regulations. In general boron leaches to a higher extent than chromium and copper. The shower test has proven to be a useful qualit...
W J Homan, H Militz
Proposal for further work on fixation of CCA-preservatives in wood
1988 - IRG/WP 3493
Many studies on the fixation and fixation-mechanism of CCA-preservatives in lignocellulose materials have been published but few on the practical consequences of this knowledge. For the wood preserving industry and the user of treated wood it is important to know what is meant by the word fixation, when fixation is complete and how fixation can be recorded in an easy way according to a non-destruc...
M-L Edlund
CCA modifications and their effect on soft rot in hardwoods. Part 2
1983 - IRG/WP 3244
The work outlined in this document is a continuation of that presented in Document No: IRG/WP/3201. The findings described in the previous paper are summarised below: a double treatment of CCB followed by arsenic (CCB+A) is more effective than a double treatment of boron followed by CCA (B+CCA) or a single treatment of CCA, CCB or CCAB in controlling soft-rot due to Chaetomium globosum in birch. C...
S M Gray, D J Dickinson
The rate of losses of creosote from power transmission poles during storage
1998 - IRG/WP 98-50101-24
The purpose of this work was to study the rate of losses of creosote from power transmission poles and its consequences on the expected life of the poles stored for a long period in horizontal position. Apart from this main target of the study, the results could allow a rough estimate of the load of creosote substances on the soil especially when the poles are stored and this load accumulates over...
Z Vassou, A Satanakis, C Koutsikopoulus, J Petinarakis
Fixation and leaching of selected Malaysian tropical hardwood after treated with CCA
2001 - IRG/WP 01-40207
The objective of this study is to investigate the fixation and leaching properties of selected Malaysian tropical hardwood (sentang wood (sapwood and heartwood) and rubberwood) after being treated with copper chrome arsenate (CCA) type-C preservative. The samples were treated with retention level of 0.5%, 2.0% and 5.0%. The samples were leached and the leachate were analyzed by AAS and the amount ...
R Hashim, O Sulaiman, Tan Siew Ching, K Yamamoto
Effectiveness of CCA fixation to avoid hexavalent chromium leaching
2002 - IRG/WP 02-50187
It is generally assumed that hexavalent chromium in chromated copper arsenate wood preservative is substantially reduced to trivalent chromium during fixation and that the potential to leach the more toxic CrVI is minimal. However, there are occasional claims some hexavalent chromium remains in wood after fixation and that small amounts of CrVI are available for leaching. One problem is that ot...
P A Cooper, D Jeremic, Y T Ung
A suggestion for the improvement of the chemical protection of wooden poles
1987 - IRG/WP 3445
Insufficient drying of white poles in Sweden causes inadequate penetration of the impregnation compounds, CCA salts and creosote, in a varying proportion of the treated poles, and with pretreatment decay present, sooner or later, internal fungal attack in the ground-line zone of the standing poles is the result. The application of a diffusing fungicide in the ground-line zone in connection with th...
H Friis-Hansen
The multi-phase pressure (MPP) process. One stage CCA treatment and accelerated fixation process
- Concepts proved by repetitive pilot plant treatments
1997 - IRG/WP 97-40079
Twenty-four charges of radiate pine roundwood or sawn timber were treated using the MPP Process and hot CCA solution. Treated timber met the CCA retention and penetration requirements of the NZ Timber Preservation Council for Hazard Classes H3 to H5. The objectives of the trials were: (1) To "stress" CCA solution by repetitive heating, treating and cooling to determine its stability in the process...
A J Pendlebury, J A Drysdale, K Nasheri, H Pearson, M E Hedley
Using image analysis to rate wood stain trials
1993 - IRG/WP 93-10034
Assessing the extent of fungal discoloration on wood during laboratory trials is a subjective process which provides an opportunity for considerable variation between individual evaluators of specimens. The development of reliable systems for automatically assessing discoloration would minimize evaluator bias and permit comparisons between results from different laboratories. The use of image anal...
C M Sexton, A G Maristany,C C Brunner, J J Morrell
Investigation of temperature effect on fixation of Celcure preservative (ACC) in beech (Fagus orientalis)
2001 - IRG/WP 01-40200
In this research, the fixation speed of Celcure 2% (ACC) preservative salt, under temperature of 17°C, 27°C and 50°C, on intact and stained wood specimens of beech was investigated. For this purpose, blocks of wood with 5x5x7 cm dimensions were prepared and saturated with 2% ACC concentration by full-cell process. The specimens were put in three incubators at the above-mentioned temperatures. F...
A Karimi, M Ghorbani
Délavabilité de bois ronds traités avec un sel CCA dans des conditions réelles de stockage. Incidence pratique de la fixation accélérée par étuvage. Impact effectif sur l'environnement
1993 - IRG/WP 93-50001-23
Un essai de terrain a été organisé pour mesurer concrètement, dans des conditions aussi proches que possibles des conditions réelles de terrain, les pertes effectives en produit de traitement lorsque le bois traité est soumis à des intempéries. L'essai a été conduit sur des bois ronds (poteaux), traités en autoclave par procédé Bethell avec un sel CCA de type C, avec comme fi...
M Rayzal, F Larroze
Comparative study on leaching of CCA from treated timber: Modelling of emission data
1994 - IRG/WP 94-50027
Results of a comparative study on leaching of CCA from treated timber are reported. The study aims at investigating the applicability of prestandard leaching test methods for modelling purposes. Prestandards used are the European standard proposed by CEN/TC38/WG11 and NEN 7345 (Dutch prestandard for building materials). Parameters of study are type of fixation, wood species (pine - spruce), specim...
G M F Van Eetvelde, M Stevens, L Van der Mijnsbrugge
Studies on the mobility of arsenic, copper and chromium in CCA-contaminated soil
1990 - IRG/WP 3571
CCA contaminated soils from six Swedish preservation plants were investigated primarily to study the mobility of arsenic but also that of copper and chromium in the soils. The soil samples represented average types with different amounts of clay, organic matter, arsenic, copper, chromium and different pH. The total soluble amounts of the elements were measured. The pH dependent solubility and the ...
J Bergholm
The environment and the timber preservation in the Benelux countries
1990 - IRG/WP 3580
The environment has become a major issue in all industries. To focus on the timber preservation industry an analysis is made of the production chain. Suggestions are made for diminishing or excluding emissions of agents of pollution. After a review of the legislation in Holland, some important statements are made on the production process, the products involved and the waste materials. Finally raw...
C De Mey, R Leegwater
Creosote for wood preservation
1971 - IRG/WP 36
By creosote one usually means coal tar creosote, although there are creosotes of other origin. For example, wood tar creosote is a product of wood distillation. It is, in fact, in this connection that the word 'creosote' was first used. Early in the nineteenth century the oily product obtained by distilling wood was said to have an odour which resembled 'smoked meat&...
Anonymous
A novel device for detecting internal defects in wooden poles
1989 - IRG/WP 2329
The diagnosis of internal defects caused by termites and decay in hardwood transmission poles has been investigated using a novel Automatic Feed Drill (AFD) pole testing device. Internal defects were recognised by changes in drill feed-rate as the automatic air-driven drill traversed its 100 mm working stroke. The instrument is portable, simple to operate and recognises defects instantaneously. Te...
R A Eaton, R S Johnstone
Effects of fixation conditions and seawater on leaching of wood treated with marine retention CCA
1997 - IRG/WP 97-50088
The effect of post-treatment conditioning temperature and humidity on leaching of chromated copper arsenate (CCA) was compared in seawater and deionized water. Southern pine cubes treated to 40 kg/m3 CCA were stored at 2° C and 82% relative humidity (RH), 24° C and 65% RH, or 32° C and 30% RH for 3, 10, or 17 days. Cubes were then leached in deionized water or artificial seawater. The rate of l...
S T Lebow
Fixation of copper-chrome-arsenic treated timber: A comparison of leaching methodologies
1996 - IRG/WP 96-50075
Five packs of kiln dried radiata pine heartwood were treated with copper-chrome-arsenic preservative treated, utilising a modified Bethell treatment schedule. Two methods of determining the level of preservative fixation were compared. These included the diphenylcarbazide method and simulated rainfall testing. The fixation levels were generally higher for tests involving simulated rain leaching. F...
S Walley, P R S Cobham, P Vinden
L-joint trials: Part 2: The relationship between colonisation by decay fungi and long-term performance
2002 - IRG/WP 02-20251
Many of the L-joint trials conducted at BRE were assessed during the early stages to establish the rate of colonisation by fungi, principally basidiomycetes. At that time, a system of assessment incorporating colonisation studies was proposed for inclusion within the European Standard EN 330 but was rejected for the final version of the standard. The long-term trials associated with the colonisa...
J K Carey
Strength properties of preservative treated pine and spruce wood after super-heated steaming
1984 - IRG/WP 3313
Possible changes of strength properties of CCF pressure impregnated pine and spruce with subsequent steaming at 110°C respective 120°C for 30 min were examined. For spruce analysis of variance indicated that none of the processes had a significant effect on bending strength, compression strength and the corresponding modulus of elasticity as well as on impact bending strength and shear strength ...
R-D Peek
Efficiency of wood impregnation processes
1980 - IRG/WP 3151
Many wood impregnation processes have been in use for a very long time, up to 150 years, but they have not been progressively modified. This paper considers impregnation processes in relation to current requirements, particularly impregnation efficiency and energy consumption. The term 'pore' is used throughout in its physical sense and is not confined to botanical 'pore...
B A Richardson
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
An initial evaluation of the environmental impact of potential marine biocides
1978 - IRG/WP 441
Pilings and other structures in the marine environment are protected primarily by impregnation with creosote alone, or in combination with coal tar or waterborne preservatives such as copper-chrome-arsenate. Some of these materials are considered as possible ecological hazards and face an uncertain future; perhaps newly developed treatments to replace these conventional ones will pose different pr...
J D Bultman, P J Hannan