Your search resulted in 31 documents. Displaying 25 entries per page.
Problems of fixation of CCA-preservatives in palm-wood
1985 - IRG/WP 3338
Palm-wood may be used for posts and poles where it needs proper treatment for long time use. Based on observations by W. Killmann on low CCA-fixation in palm-wood, samples of Jubaea-palm grown in a Greenhouse at Hamburg, have been treated in two different series with a 4% solution of CCA-type B. After 1-16 weeks of storage the blocks were split into sticks of 1-2 mm² and leached. In all series 50...
H Willeitner, K Brandt
Studies on accelerated ageing procedures with TBTO-treated wood
1985 - IRG/WP 2244
The efficacy of various procedures for accelerated ageing of organotin based wood preservatives in treated wood has been investigated. It was found that leaching of the treated wood samples in water according to the European Standard EN 84 was not satisfactory for organotin based preservatives and is probably also unsuitable even for other types of organic solvent preservatives. Keeping tributylti...
J Jermer, M-L Edlund, B Henningsson, W Hintze
The permanence of permethrin in wood preservation
1984 - IRG/WP 3288
The permanence of the synthetic pyrethroid permethrin in treated wood has been assessed for double vacuum and immersion treated Scots pine sapwood and whitewood using a 0.5% m/m solution of the insecticide in a hydrocarbon solvent. It is concluded that for all but the outermost 0.5 mm of the treated battens the distribution of the permethrin is relatively permanent. The outermost 0.5 mm appears vu...
R J Orsler, M W S Stone
Literature survey on the permanence and distribution of salt-type wood preservatives
1969 - IRG/WP III 1B
The objective of this survey is generally to review some of the more important published work dealing with the distribution and permanence of salt-type waterborne wood preservatives in treated timber. The survey is limited to the major chrome-containing formulations and the classification system proposed by Becker (1964) has been adopted throughout.
CK - chromium, copper (copper, chrome); CKA - c...
Anonymous
Soil-bed studies (Part 3): A cause of failure of multisalt preservatives following soil-bed exposure
1983 - IRG/WP 3261
P Vinden, J F Levy, D J Dickinson
CCA Chemistry
1983 - IRG/WP 3268
A Pizzi
Investigation of the fixation in wood of chromated zinc chloride and copperised chromated zinc chloride preservatives
1976 - IRG/WP 372
A biological method of evaluating the extent to which CZC and CCZC preparations are retained in wood in terms of the potential protection which they afford against destruction by Merulius lacrymans (dry rot) is given. CCZC is recommended for protection of wood under moderate leaching conditions, while the use of CZC under such conditions is not recommended....
V N Sozonova, D A Belenkov
Stability and performance of tributyltin compounds
1984 - IRG/WP 3275
Based on the critical examinations of the disputable permanence of tributyltin compounds in wood, this paper deals with a number of examinations of the relative evaporation, thermal stability and oxidation stability of some TBT-compounds. While thermal and oxidative stability is high for all TBT-species, the relative evaporation at elevated temperature is highly variable, and lowest for the TBT-es...
F Imsgard, B Jensen, H A B Landsiedel, H Plum
The course of fixation of Cu-Cr-As wood preservatives
1972 - IRG/WP 307
Copper-chrome-arsenic (CCA) preservatives in contact with wood result in an instant extensive increase of pH, because of ion-exchange and adsorption reactions with the wood. During precipitation of the active elements the pH continuously increases but reaches a maximum, when all chrome is consumed. Some of the early reaction products are unstable and slowly convert via dissolution into stable comp...
S-E Dahlgren
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
Chemical and biological studies of organotin treated and painted wood stakes after outdoor exposure
1987 - IRG/WP 3419
Organotin based wood preservatives containing tributyltin oxide (TBTO) or tributyltin naphthenate (TBTN) are used in Sweden mainly for double-vacuum treatments of window joinery of Pinus sylvestris. After impregnation the joinery is painted or stained in different colours. To evaluate this effect (different colours on the degree of degradation of TBTO and TBTN, effected by different temperatures i...
M-L Edlund, B Henningsson
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
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
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
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
Permanence of permethrin and bifenthrin in framing timbers subjected to hazard class 3 exposure
2005 - IRG/WP 05-30383
End-sealed Pinus radiata specimens measuring 235 x 90 x 35 mm were treated using a modified Lowry schedule with permethrin or bifenthrin in white spirit to Hazard Class 2 (H2) retentions. After conditioning, the specimens were exposed at 45o on north facing racks near Melbourne (Australia). Samples of the specimens were taken before installation, and after three and six months exposure. Analyses o...
A C Hunt, D G Humphrey, R Wearne, L J Cookson
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
Field evaluation of CCA movement in sap-displaced copper chrome arsenic treated softwood poles
1989 - IRG/WP 3539
Commercial sap-displaced UK grown Scots and Corsican pine, and Sitka and Norway spruce poles were exposed in a field site at Dundee, Scotland and radial distribution profiles of CCA monitored prior to implantation and after subsequent field exposure. Results show that groundline levels of all preservative elements were higher after 1 and 2 years field exposure compared with those recorded prior to...
S D Hainey, G M Smith, A Bruce, P D Evans, B King, H J Staines
European standardization for wood preservation
1991 - IRG/WP 2365
Since the last IRG 21 conference in New-Zealand, there one meeting of the plenary committee and several meetings of working groups. The interprative documents prepared by CCE for expliciting the essential requirements of the CCE Directive on the construction products and specially: mechanical resistance and stability / hygiene, health and environment / safety in use
are waited to valid the progra...
Anonymous
Experiments in accelerated ageing
1984 - IRG/WP 2223
Experiments using a vacuum oven to accelerate the evaporative loss of g-HCH from treated wood blocks have indicated that the method described in this paper has the potential to reproduce in a relatively short time the distributions and loadings of the insecticide that are found during natural ageing. By contrast, the wind tunnel removed the volatile material in a way not found in natural ageing an...
R J Orsler, M W S Stone
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
Bibliography on the use of boron compounds for the preservation of wood
1973 - IRG/WP 315
This bibliography is based on an earlier literature survey prepared by J. Thornton and Wm. E. Bruce (O.E.C.D. Document No. 27/DAS/CSI/M/91) which was enlarged and revised for a meeting in Paris in October 1968 (Document 27/DAS/CSI/M554) by Professor W. Bavendamm of Reinbek. The latter (1968) document with its 166 references has now been extended and brought up to date. Acknowledgments are due to B...
R Cockcroft, J F Levy
Chemical and biological investigations of double-vacuum treated windows after 7½ years in service
1985 - IRG/WP 3339
Earlier investigations of double-vacuum treated windows after five years in service have shown that tributyltin oxide (TBTO) degrades to di- and monobutyltin compounds and that the resistance of the wood against decay decreases. An investigation 2.5 years later of the same windows shows that the degradation of TBTO proceeds fast. After 7.5 years in service only 15-35% of the remaining organotin co...
M-L Edlund, J Jermer, B Henningsson, W Hintze
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