IRG Documents Database and Compendium

Search and Download IRG Documents:

Between and , sort by

Displaying your search results

Your search resulted in 26 documents. Displaying 25 entries per page.

Proposal for further work on accelerated ageing
1988 - IRG/WP 2314
M-L Edlund

Influence of different fixation and ageing procedures on the leaching behaviour of copper from selected wood preservatives in laboratory trials
2003 - IRG/WP 03-20264
The paper focuses on the role of different parameters, such as fixation, sample size, wood species, and leaching in internationally standardized ageing procedures for wood preservatives from Europe, Japan and the United States. The leaching protocols used were EN 84, JIS K 1571 and AWPA E11 protocols. The wood species were Scots pine, Sugi and Southern Yellow Pine respectively. Three types of commercially important copper-based wood preservatives were used as model formulations, namely copper/copper-HDO, ammoniacal copper/quat and CCA. The most important factors determining the extent of copper leaching in the different lab trials were the sample size (volume/surface ratio) and the fixation conditions prior to leaching. On the other hand, the wood species and the leaching protocol itself were found to have only minor influence on the copper leaching rate in the test methods included in this study.
J Habicht, D Häntzschel, J Wittenzellner

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 tributyltin oxide (TBTO) treated samples in a heating cabinet at 70°C for five weeks, however, had a considerable effect on the breakdown of TBTO and the subsequent decay test. Therefore, an ageing procedure involving a heating period should be considered for all organic solvent wood preservatives. The investigation also confirmed that elevated temperatures accelerate the degradation of TBTO and that there is a strong correlation between the percentage of TBTO in the wood and its resistance against decay.
J Jermer, M-L Edlund, B Henningsson, W Hintze

Report on the activities of the European Standardization Committee CEN/TC 38 'Methods of Testing wood preservatives'
1980 - IRG/WP 279 E
G Castan

Fungicidal combination products
1987 - IRG/WP 3426
Due to the increased pressure on some of the established fungicides used in wood preservation, possible alternative products become more interesting. The requirements for new chemicals are mainly lower toxicity and greater environmental acceptability. However the efficacy to target organisms should be as good as that of the currently used ones, preferably better. A possibility for progress in this direction could be fungicidal combination products showing broader spectrum of efficacy and synergistic effects. Mixtures of tributyltin compounds with Furmecyclox and K-HDO respectively are tested for this purpose. Toxic values with and without artificial ageing (wind-tunnel exposure and leaching) were determined. Investigations have been made with coating-formulations in order to test penetration, evaporation and the influence of UV-radiation. Aqueous formulations were tested for special purposes such as the treatment of freshly cut timber and the protection of brickwork. The results obtained are very promising, especially regarding long term durability. Further investigations mainly with the aqueous formulations including other test fungi and field trials are necessary to confirm the suggested application as wood preservatives.
H A B Landsiedel

Rapport sur l'activité du CNE/TC 38 'Méthodes d'essais des produits de préservation du bois'
1980 - IRG/WP 279
G Castan

A comparison of the effectiveness of a vacuum oven and a wind tunnel in the accelerated ageing of treated wood by evaporation
1989 - IRG/WP 2334
R J Orsler, G E Holland

Checking of sodium pentachlorophenate fixation in wood
1990 - IRG/WP 3620
In order to estimate the volatilization of sodium pentachlorophenate from treated wood, wood samples treated with pentachlorophenate were analysed after various durations of an EN 73 weathering The results giving no clear evidence of volatilization, treated wood samples were put in a test chamber with precise climatic conditions, the air used in the experiment being analysed. The pentachlorophenate content in air was quantified: 1.8 µg/m³
M Lamour, H Sageot

The potential for accelerated ageing to determine the persistence of active ingredients in timber
2006 - IRG/WP 06-20323
Fast screening methods for evaluating the persistence of active ingredients in timber are proposed. This is an outline proposal which is intended to provoke discussion and further development of the methods. Reliable and accurate analytical methods are key to these tests.
L D A Saunders, M R Powell

Accelerated ageing of preservatives in treated wood
1988 - IRG/WP 3476
New preservatives are tested in the laboratory and often in field tests before they are used commercially. Some preservatives, however, tested in the laboratory do not show the expected stability when used in service. The differences between laboratory tests and practical use can never be completely eliminated but must be minimized as far as possible by relevant testing methods. Studies of the effect of different accelerated ageing procedures on the chemical degradation and the wood preserving capacity of six different fungicides or combinations thereof have been carried out. Chemicals tested were tributyltinoxide (TBTO), tributyltin naphthenate (TBTN), furmecyclox, benzalkoniumchloride (AAC) + guazatin and pentachlorophenol. The ageing procedures included exposure of test specimens in a wind tunnel (according to EN 73), in an oven at 40°C, 60°C and 70°C, leaching (according to EN 84) and combinations of these procedures. The influence of the different accelerated ageing procedures on the chemical degradation and toxic effect of different fungicides was obvious and, for some procedures and chemicals, comparable with experiences from practice.
M-L Edlund, B Henningsson, B Jensen, C-E Sundman

Decrease of the antidecay resistance of beech wood treated with organotin fungicides after its natural ageing
1998 - IRG/WP 98-30185
The antidecay resistance of beech-wood samples (120 x 8.5 x 8.5 (MM)) treated with tributyltin fungicides gradually decreased due to prolongation of their natural ageing: tributyltin fungicides (TBTO, TBTS, TBTCA, TBT-DEDTK were applied by pressure impregnation technique in ethanole solutions (c = 0. 1%, 0.33% or 1%); treated beech-wood samples were naturally aged without their contact with ground (from 0 to 4 months); the antidecay resistance of treated and aged beech samples was tested against the brown-rot fungus Serpula lacrymans and white-rot fungus Coriolus versicolor, and then evaluated on the basis of their weight losses (DmF) and their relative impact bending strength decreases (DAF(rel)). The statistical evaluations indicated that: toxic values [kg/m3] of tributyltin fungicides have been significantly increased due to natural ageing processes; tributyltin fungicides were more effective against the brown-rot fungus Serpula lacrymans; both criteria DmF and DAF(rel) have been, on the whole, comparable when assessing the early stages of rot in the unsatisfactorily treated beech samples, although decreases of DAF(rel) were several-times higher than of DmF; however, for the higher stages of decay (DmF > 8%) just the AmF criterion could more sensitively express the further increasing differences in rot.
L Reinprecht

Xenon simulation of natural weathering of external joinery preserving - Finishing systems
1992 - IRG/WP 92-2412
Semitransparent wood stains ('lazures') for external joinery have developed by means of product combination towards complete wood finishing systems that are easy to applicate, have a good weathering resistance and low maintenance cost. The search for enhanced formulations and the possibilities to standardize these products or treatment systems are always facing long periods of weathering tests. Extensive research was conducted to compare natural weathering with artificial ageing, using a scheme based on two cycle units commonly used for artificial weathering and intermediate low temperature exposures. Statistical analysis of test results showed good similarity between both natural weathering and Xenon ageing
J Van Acker, M Stevens, M Nys

Durability of plywood made from soft- and hardwoods assessed according to ENV 12038 after artificial and natural ageing
2000 - IRG/WP 00-20191
Plywood was prepared from Norway Spruce and pure heartwood of Douglas Fir, Scots Pine, European Oak, False Acacia and Macoré using a phenol-formaldehyde glue. The panels of 38 mm in thickness were pre-conditioned according to the following procedures: a) 12 weeks storage at 20°C/65% rh, b) 2 weeks artificial weathering (with rain and UV-radiation at changing temperatures), and c) a natural weathering according to ENV 12037 for 3 month, 6 month and for 9 month whereby the ENV 12038 specimens were cut from the lap-joints. In general for softwood panels the decay was lowest after a 12 weeks` storage and the artificial weathering increased the decay rate more than the natural weathering applied. For False Acacia the durability was gained as predicted by EN 350-2 but not for the other species. Especially for European Oak and Macoré the durability was much lower than expected. Further, it has to be mentioned that the specimens usually showed a more intensive attack close to the nutrient media than at the top of the specimens. This indicates that the laboratory results might be influenced by the thickness of the panel tested because thinner material would be more equally degraded and thus would show a lower grade of durability.
H Leithoff, R-D Peek

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 in the wood), stakes of Pinus sylvestris sapwood were treated with TBTO or TBTN, painted in different colours and exposed outdoors out of ground contact.
M-L Edlund, B Henningsson

Laboratory tests on artificial weathering of Quercus rubra crossties
1986 - IRG/WP 2252
Clear red oak (Quercus rubra) blocks were used to evaluate various types of accelerated aging tests including boil, steaming, and cyclic weathering. It was found that the repeated vacuum and pressure treatment of wood in water, steaming, oven-dry, and freezing appeared to be most effective in reducing the MOE in compression and hardness modules of wood specimens. Red oak crossties which were pressure treated with creosote - coal tar preservative were tested using the cyclic aging technique. This method will be used to establish correlation between short-term accelerated aging test results and long-term in service performance of wood crossties.
P Chow, A J Reinschmidt, E J Barenberg, S L Lewis

Laboratory evaluation of chlorothalonil against the Formosan subterannean termite
1992 - IRG/WP 92-1559
The fungicide chlorothalonil was evaluated as a wood preservative to prevent attack by the Formosan subterranean termite, Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae). Southern yellow pine wafers treated with chlorothalonil (CTL) in P9 oil, CTL + chlorpyrifos in P9 oil, or CTL in xylene were conditioned by evaporative aging at 40° C for 4 weeks and exposed to termite attack in a modified ASTM D3345 4-week laboratory test. Actual CTL retentions were assayed post-test by X-ray fluorescence, and an approximate 50% decrease in CTL concentration found from the pretest nominal CTL retentions. With all three treatments, termite feeding on wood with actual retentions of 0.05-0.10 pcf (corresponding to 0.10-0.21 pcf nominal) did not differ significantly from the respective solvent controls. CTL retentions of 0.13-0.15 pcf (0.41-0.45 pcf nominal) limited wood weight loss from termite feeding to 6-13%, and retentions of 0.26-0.39 pcf (0.81-0.94 pcf nominal) CTL resulted in only 3-4% wood weight loss. Termite mortality was correlated with CTL retention. These results demonstrate that chlorothalonil is toxic to termites, and at the appropriate retention will deter Coptotermes formosanus from feeding on treated wood.
J K Grace, P E Laks, R T Yamamoto

Growth of sapstain fungi in scots pine and the effect of timber ageing
1998 - IRG/WP 98-10269
A trial was initiated to study the growth of known isolates of sapstain fungi in scots pine (Pinus sylvestris) which had been naturally aged or sterilised by autoclaving or irradiation. Sawlogs cut from commercial thinnings were reduced to billet size and the exposed ends were painted with a bituminous sealant to reduce moisture loss. Some billets were inoculated after autoclaving or gamma-irradiation when freshly felled (time zero) or when nine weeks old. Other non-sterilised billets were inoculated at time zero, three, six and nine weeks. The fungal inocula comprised two isolates each of Leptographium wingfieldii, Ophiostoma piceae, and Sphaeropsis sapinea, which were introduced into the billets below the bark and incubated at 20°C. After two weeks, the bark was removed and the sapwood lesions were measured and recorded photographically. The three species showed different growth characteristics over the trial. 0. piceae had the poorest growth, which increased slightly as the logs were aged. The two isolates of L. wingfieldii differed in colonising ability, but both showed the greatest growth between time zero and three week old logs followed by a decline in growth rate over the rest of the trial. S. sapinea was the most vigorous coloniser, but showed a more or less steady decline in colonising ability as the logs aged. All the fungi exhibited faster rates of growth in freshly felled logs which had been sterilised by autoclaving or irradiation. The lesions exhibited zonation: outer healthy tissue, a central area of stained tissue and an intermediate pale zone. The pathogenic/saprotrophic nature of the inoculated fungi is discussed and related to the condition of the timber.
N J Strong, J F Webber, R A Eaton

Creosote losses due to ageing methods prior to laboratory efficacy testing
2002 - IRG/WP 02-20256
Laboratory efficacy testing of creosote is affected by the impact of volatile components on the fungal growth. European test methods for assessing efficacy against Basidiomycetes and soft rot fungi is based on two standard methods, EN 113 and ENV 807 respectively. Combined with both fungal tests two pre-treatment methods are commonly used, namely EN 84 (leaching) and EN 73 (evaporation). Within the activities of the European research project "WOODPOLE" the impact of both ageing methods has been compared with several alternative methods using a gravimetric approach. The three creosote types defined by the Western European Institute for wood preservation (WEI) as types A, B and C have been used to treat wood blocks as in EN 113. Mass loss due to ageing revealed not only the importance of the diluting solvent used but also the impact of the creosote type. Since both EN 84 leaching and EN 73 evaporation proved to eliminate a considerable part of the absorbed creosote mass, it is suggested that prior to laboratory fungal testing for hazard class 4 applications (EN 335) a consecutive ageing of evaporation and leaching according to the existing standards should be applied. The conclusion that we came to and have used in the subsequent testing was that two different methods of ageing should be performed for Basidiomycete and softrot testing i.e. (1) for EN 113 ageing the EN 73 evaporation (12 weeks wind-tunnel exposure) and the EN 84 leaching after open air ventilation; and (2) for ENV 807 the initial ageing is based on EN 73 evaporation in the wind-tunnel, or a 12 weeks open air ventilation prior to the required EN 84 leaching.
J Van Acker, K Ghekiere, M Stevens

Artificial weathering exposure as an alternative for standard ageing according to EN 84 (leaching) and EN 73 (evaporation)
2002 - IRG/WP 02-20254
In order to verify potential weaknesses of wood preservatives fungal tests are carried out after ageing of wood preservative treated test blocks. The European standard EN 599 as a framework for efficacy assessment of wood preservatives includes the use of two ageing methods prior to fungal testing, namely a leaching method (EN 84) and an evaporation method (EN 73). The European research project "F.A.C.T." aimed amongst other objectives to provide in more realistic alternatives for both ageing methods. Artificial weathering systems generally used to assess the weathering resistance of exterior coatings was looked at as an alternative. For this purpose artificial weathering devices were selected which besides a control of temperature and light also allow for the impact of moisture by means of water spraying. UV cabinets with spray option were used to evaluate the effect of ageing of three wood preservatives: a waterborne Cu-HDO preservative, an oilborne triazole combination and a TBTO reference preservative. Based on EN 113 Basidiomycete testing of aged specimens a range of equivalent UVS systems proved to be suitable as an alternative ageing system prior to EN 84 and EN 73.
J Van Acker, M Grinda, D J Dickinson

Cyclic delamination analysis of preservative-treated wood/FRP interfaces
2002 - IRG/WP 02-40244
Wood preservative chemicals can interfere with adhesive properties when bonding wood laminates or wood/FRP (Fiber Reinforced Polymer) laminate composites. In this work we studied the effects of various wood preservative treatments, and pre- and post-treatment on wood/wood and wood/FRP bond durability using a severe cyclic delamination test (ASTM D-2559). Pre-treatment of individual laminates with oil-borne (copper naphthenate, creosote and pentachlorophenol) and water borne (CCA and CDDA) preservatives increased the delamination between the wood and FRP, although wood/wood bonds were generally acceptable. Post-treatments had limited effect on wood/wood delamination. The use of post-treatments on wood/FRP bonded samples, although less significant than with pre-treatments, also increased delamination of wood/FRP glue lines.
C Tascioglu, B Goodell, R Lopez-Anido

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 and characterised principally by the rapid removal of material close to or on the wood surface. Theoretical considerations reinforced these practical observations indicating that the vacuum oven could provide a much quicker means of attaining the condition that is likely to exist in aged timber.
R J Orsler, M W S Stone

Stability, performance and distribution of propiconazole (R 49362) in acceleratedly aged wood
1991 - IRG/WP 3647
The permanency of propiconazole (R 49362 - WOCOSENÔ technical - Janssen Pharmaceutica) in wood was examined in an 18 month storage test, an evaporative ageing study (EN 73), a volatilization stress experiment, and water-leaching studies (EN 84). The biological efficacy against two brown rot fungi: Coniophora puteana BAM Ebw. 15 and Gloeophyllum trabeum BAM Ebw. 109 was assessed according to the European Standard EN 113 with and without acceleratedly aged blocks of Scots pine sapwood (Pinus sylvestris L.). Propiconazole proved to be leach-resistant from treated wood. Evaporative ageing had very little effect on its biological performance. Chemical analyses of various Scots pine sapwood (Pinus sylvestris) samples used for EN 113 testing, showed that the concentration gradient in the outermost shell of the wood specimens was not altered by accelerated ageing stresses and that the active ingredient is evenly distributed in the wood substrate. These results indicate that propiconazole is suited for further development as a fungicide for pressure-treated timber.
A R Valcke, M Stevens

Accelerated weathering test for the evaluation of wood preservative efficacy
2003 - IRG/WP 03-20262
Wood samples treated with ammonium copper quat (ACQ-1900 and ACQ-2200), Chromated copper arsenate (CCA), Tanalith E 3491 and Wolmanit CX-8 have been studied in accelerated weathering experiments. The weathering experiment was performed by cycles of 2 hours UV-light irradiation followed by water spray for 18 minutes. The changes on the surface of the weathered samples were characterized by FTIR Spectroscopy and color measurements on the samples with 0, 200, 400 and 600 hours of total weathering. The objective of this study was to investigate the changes created by weathering on impregnated wood with several different wood preservatives. This was performed study, accelerated weathering using UV irradiation and water spray was used to simulate natural weathering. FTIR and color measurement was used to investigate the changes after several intervals (0- 200 h- 400 h- 600 h) in artificial weathering of treated and untreated wood.
A Temiz, M Eikenes, Ü C Yildiz, F G Evans, B Jacobsen

Comparative study of blue stain resistance of various types of wood stains after artificial and natural weathering
1992 - IRG/WP 92-2411
For the determination of the protective effectiveness of a preservative treatment against blue stain in service, artificial weathering has been proposed as an alternative for the natural weathering period of 6 months in the European standard EN 152. Research on a range of products and on complete finishing systems for external joinery was conducted during 1986-1990. It revealed that the decisions drawn after 4 weeks Xenontest do not always confirm those of the EN 152 natural weathering test. Results were influenced by the nature of the formulation, the resin binder and the product combination (treatment system). However the variation among the ageing methods generally does not effect the practical conclusions on the blue stain resistance when well-defined limits are considered.
J Van Acker, M Stevens, M Nys

New research data confirming the suitability of bifenthrin as a wood preservative
1996 - IRG/WP 96-30116
Bifenthrin has been further tested against wood destroying insects, and its behaviour in wood has been extensively studied. Bifenthrin proved to be highly effective as a curative and preventative treatment against Anobium punctatum and Hylotrupes bajulus, after both leaching and evaporative ageing. Results of penetration tests with water and solvent based formulations, applied by brushing, dipping and double vacuum confirmed the good performance of bifenthrin in wood of Scots pine and beech. The new results confirm the promising characteristics of bifenthrin as highly effective and stable insecticidal wood preservative.
S Shires, P Héloir, B Chen, G Rustenburg

Next Page