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Blue Stain Testing of Alkyd and Acrylic Stains
2003 - IRG/WP 03-20273
Resistance against blue stain of semi-transparent alkyd and acrylic stains was tested by both EN 152 and the so-called reverse exposure test methods. Comparison of the results, obtained by both methods was the most important aim of this study. As expected, performance of the water-borne acrylic paint was lower compared to protective effectiveness of the alkyd stain. This difference was even more pronounced when artificially accelerated aged samples were exposed. It seems that the reverse exposure method may give more distinctive results. In general, our results confirm previous literature reports on adequacy of the reverse test method for evaluation of blue stain resistance of surface finishes.
M Petric, M Pavlic, B Kricej, M Humar, F Pohleven

The susceptibility of acetylated Pinus radiata to mould and stain fungi
1992 - IRG/WP 92-1548
The aim of this investigation was to determine the effect of 5, 10, 15 and 20 percent acetylation weight gains on the susceptibility of Pinus radiata sapwood to mould and stain fungi, and to establish if an acrylic paint, an oil-based stain and a water repellant gave superior protection from fungal growth on wood treated to 20% acetylation weight gain, compared to untreated wood. One treatment set was tested using a modified anti-sapstain screening trial method, designed to give optimal conditions of relative humidity (>95%) and temperature (25°C) for mould growth. A second treatment set was exposed to the weather and assessed at 10, 21 and 40 weeks. The results showed that over the three week laboratory trial period, the rate of colonisation by mould fungi of Pinus radiata sapwood treated to 20% acetylation weight gain was significantly (P < 0.001) slower than on untreated wood. This was attributed to the lower availability of readily assimilated nutrients such as sugars and starch in acetylated wood. The rate of colonisation by mould fungi of acrylic-finished sapwood treated to 20% acetylation weight gain was significantly slower than on acrylic-finished untreated wood. Acetylation up to 20% weight gain conferred no protection from mould growth for test samples exposed to the weather. None of the finishes perfomed better on acetylated wood than non-acetylated wood when exposed to the weather.
R N Wakeling, D V Plackett, D R Cronshaw

Black-stain Resistant Acrylic Latexes for Wood Coatings Applications
2017 - IRG/WP 17-40786
Translucent coatings on wood in exterior applications often fail due to photodegradation and colonization by black-stain fungi and require frequent refinishing. This limits competitiveness with alternative materials. In this project, it was hypothesized that an effective dispersion of inorganic nanoparticles will provide a translucent coating with long-term resistance to black-stain fungi. Functionalized silver nanoparticles with a mean particle size of 12 nm were incorporated in acrylic polymer particles by miniemulsion polymerization. This polymerization technique has been selected over the traditional emulsion polymerization to encapsulate inorganic particles into polymer particles and prevent the agglomeration of inorganic nanoparticles. In previous work, it was found that latexes containing silver nanoparticles showed antifungal activity against Epicoccum nigrum, and a mix of Penicillium funiculosum and Aspergillis niger at low silver concentration (0.1% m/m) (Boivin, Ritcey and Landry, 2015). Based on these results, acrylic latexes containing different concentrations of silver nanoparticles were mixed with a commercial acrylic resin. The formulations were applied on ponderosa pine (Pinus ponderosa) sapwood and fungal resistance was evaluated against three species Aureobasidium pullulans, Sclerophoma pityophila and E. nigrum. Latexes with concentrations of silver nanoparticles as low as 0.03% were able to control S. pityophila and E. nigrum, while higher concentrations were needed to control A. pullulans.
G Boivin, A M Ritcey, P I Morris, V Landry

Bacterial adhesion to selected wood finishes
2017 - IRG/WP 17-40793
A new generation of furniture, including antibacterial surfaces, should adjust to the changing needs of an ageing population. Respectively, determination of bacterial adhesion on wooden surfaces, finished with various wood finishes or coating is an important topic. The main aims of our work were of a preliminary character. We wanted to state if the existing methods for testing of bacterial adhesion on different surfaces could be implemented on wooden surfaces coated with some common surface finishes. It was shown that wood coatings and finishes on wood could be tested for adhesion of bacteria, when the established procedures are adapted for wood as a specific substrate material. It seems that Pseudomonas aeruginosa adhesion level was different on selected finishes. Our preliminary results showed that the lowest one was on the hydrophobic and olephobic silane formulation treated laminated beech wood and the highest one on linseed oil. This tentative indication should be confirmed with extensive experiments in future.
M Petrič, D Kekec, J Žigon, K Godič Torkar, K Bohinc

Screening potential preservatives against stain and mould fungi on pine timber in Zimbabwe
1995 - IRG/WP 95-30063
The search for environmentally and toxicologically safer chemicals for use in the timber preservative industry against stain and mould fungi has been intensified during the past few years. Results of field tests with two chemicals previously evaluated in the laboratory are presented. The conventional sodium pentachlorophenate was the more efficacious chemical against stain and mould fungi, providing up 90% control at a concentration of 2.5%. A potential alternative, Stopstain a borate-based chemical, gave results only slightly better than the untreated control timber, at a concentration of 5%. Unless the environmental cost and toxicological hazards of traditional chemicals are highlighted the newer and safer chemicals will be reluctantly accepted by industry as they are regarded as being prohibitively expensive.
A J Masuka

Blue stain in service on wood surface coatings. Part 3: The nutritional capability of Aureobasidium pullulans compared to other fungi commonly isolated from wood surface coatings
1993 - IRG/WP 93-10035
The nutritional capability of Aureobasidium pullulans was previously examined, using agar plate tests, with regard to nutrient sources that are potentially available in fresh and weathered wood (Sharpe and Dickinson, 1992). This study compared these findings with the nutritional capability of four other fungi (Alternaria sp., Cladosporium cladosporoides, Stemphylium sp. and Trichoderma sp.) commonly isolated from wood surfaee coatings. The liquid culture techniques were used to assess the relative abilities of the fungi to utilise a range of simple sugars, wood sugar alcohols, hemicelluloses, cellulose and lignin degradation compounds. The observations were used to explain why Aureobasidium pullulans is able to occupy so successfully, often in monoculture, the wood-paint interface niche.
P R Sharpe, D J Dickinson

Low temperature drying conditions of Pinus radiata wood for avoiding internal stain
1989 - IRG/WP 3507
It has been observed that, if in little sawmills, timber is dried with a low temperature schedule, it arrives at destination with internal sapstain besides of superficial mould. In this study, the lowest drying temperature at which wood should be exposed for sterilization, which results to be 52°C, is searched. It is not possible to avoid entrainment of pentachlorophenol, even though a waiting period of 72 hours after dipping the wood in a pentachlorophenate/borax solution before drying is considered. The residual content of pentachlorophenol in wood should be at least 400 µg/cm² or the moisture content less than 23% for avoiding the development of mould.
M C Rose

Leaching of components from water-borne paints and fungitoxic effects
1995 - IRG/WP 95-20062
Water-borne model paints, acrylics and alkyd emulsion paints, of known composition were leached according to a procedure modified in accordance with ASTM 6271.1. The effectiveness of fungicidal compounds in the painted specimens before and after leaching was evaluated with a biotest in which Penicillium brevicompactum was used as a test fungus. The leaching of the fungicide Troysan Polyphase according to the biotest varied to a high extent depending on differences in paint composition. Fungicide efficiency in relation to paint formulation and fungicide mobility in a paint film is briefly discussed.
J Bjurman

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

Proposed standard laboratory method for testing fungicides for controlling sapstain and mould on unseasoned lumber
1977 - IRG/WP 292
This laboratory method is for determining the effective concentration, or concentration for zero growth (CGo), for fungicides or preparations of fungicides which are potentially useful in protecting packaged or unseasoned lumber in storage and shipment from biodeterioration by sapstain fungi and moulds. The test is rapid and may be completed in three weeks and gives a good indication of the toxicity of a chemical against sapstain fungi and moulds.
A J Cserjesi

Mould resistance of lignocellulosic material treated with some protective chemicals
1984 - IRG/WP 3294
Effectiveness of preserving lignocellulosic material against moulding by treatement with water solutions of commercial wood preservatives and mixtures of various inorganic salts was investigated and compared with the effectivenes of sodium pentachlorophenoxide and boric acid.
K Lutomski

Field trials of anti-sapstain products. Part 1
1991 - IRG/WP 3675
The results obtained in two field tests of anti-sapatain products, carried out in four locations in Portugal, are presented. Boards from freshly cut logs were hand-dipped, close staked and left to dry for periods from four to six months. The results obtained seem to indicate that some of the products tested performed at least as well and sometimes better, than a 3% NaPCP solution which was used as control product.
L Nunes, F Peixoto, M M Pedroso, J A Santos

Evaluation of the effectiveness of three microbiocides in the control of sapstains
1982 - IRG/WP 3212
Results of field test on the effectiveness of BUSAN 30, CAPTAN, FOLPET against mould and sapstain in Pinus elliottii are presented. The viability of use of FOLPET in Brazil as an alternative to sodium pentachlorophenate is also discussed.
S Milano, J A A Vianna Neto

Tebuconazole, a new wood-preserving fungicide
1990 - IRG/WP 3634
TEBUCONAZOLE, an anti-fungal triazole compound, has been tested to assess the effectivness as wood preserving fungicide. Tests were made with the active ingredient and also in formulations against basidiomycetes, blue-staining fungi and mould. Results of the DESOWAG laboratories and also from official institutes will be presented. In addition to this there were made different toxicological and ecotoxicological trials according to OECD and EPA guidelines
B Wüstenhöfer, H-W Wegen, W Metzner

Blue stain in service on wood surface coatings. Part 2: The ability of Aureobasidium pullulans to penetrate wood surface coatings
1992 - IRG/WP 92-1557
The ability of Aureobasidium pullulans to penetrate seven different wood surface coatings was examined. Eight isolates of Aureobasidium pullulans were used. Following penetration, light microscopy was used to examine the effect of the fungus upon the coating, and growth at the wood-film interface. The fungus showed different growth capabilities with different types of surface coatings. Some isolates were able to penetrate alkyd based coatings, but were unable to grow in the film. In contrast, after penetration through latex based coatings several isolates were able to produce growth in the films themselves.
P R Sharpe, D J Dickinson

Scientific development for prolonging the service life of timbers by impregnating with creosote or organic solvent type preservatives in which additive has been incorporated
1977 - IRG/WP 382
Chemically impregnated wood has played a prominent part in the Telephone and Electricity Distribution Industry during the past century and there is no doubt that it will play an equally prominent part in the future. The reasons why wood poles and wooden, structures predominate, are that when adequately chemically impregnated with a recognised timber preservative to ensure the expected service life for the purpose envisaged, the timber is then fully protected against the ravages of wood destructive organisms. Furthermore, wood is endowed with many natural characteristics that make it a favourite pole and structural material. Its high strength, light weight, ability to absorb impact or shock from loads suddenly applied and ability to resist overloading for brief periods plus its well-known insulating qualities - all are important basic reasons for its predominance in pole line structure. The use of chemically impregnated timber often makes it possible to carry out a given construction programme at less cost, or to erect more structures for a given sum of money, than when more expensive construction materials are employed.
P R B D De Bruin

Blue-stain fungi (Ceratocystis spp.) found in Spain on pine woods
1989 - IRG/WP 1410
So far, there is only a very limited reported description of the different Ceratocystis spp. present on fresh wood in Spain. So, the main goal of this work has been the identification of species of this genus causing blue-stain on Pinus pinaster A. Ait. and Pinus sylvestris L. woods. We have also investigated the relationship between the species found and their propagation vectors (insects and wind). Finally, we have determined the growing velocity of two of the most representative species found and the presence or absence of degradative enzymatic activities.
M T De Troya, A M Navarrete

Relationship between stacking, location and antisapstain preservatives on visible degrade of Eucalyptus regnans and Pinus radiata boards
1999 - IRG/WP 99-20162
An antisapstain trial was established at a Eucalyptus hardwood sawmill in Victoria, Australia. The trial incorporated two commercial formulations of antisapstain preservatives, used at four different concentrations on both hardwood (Eucalyptus regnans F. Muell) and softwood (Pinus radiata D. Don) boards. The trial also utilised different stacking methods (block-stacked, sticker-stacked, and block-stacked and wrapped in black plastic) and included replicates placed both outside in the drying yard, and inside under cover from the elements. The variation in stacking methods and in location was used to provide a variation in the fungal hazard. Worst degrade (mean of 83% at 36 weeks) was obtained for the hardwood block-stacked outside and wrapped in black plastic. Lesser extents of degrade were obtained for sticker-stacked hardwood outside (4.3%) and sticker-stacked hardwood under cover (1.2%). Degrade of softwood was less than that of hardwood under all conditions. Statistical analysis of the trial indicated that the probability of any individual hardwood board deteriorating outside was nearly 4 times greater than for a board kept undercover. In addition, the probability of degrade of a hardwood board which was block-stacked and wrapped in black plastic was 3.4 times that of a hardwood board which was block-stacked but not wrapped, which in turn was 10 times that of a hardwood board which was sticker-stacked. The probability of degrade in untreated hardwood timber was 20 times that of degrade in preservative-treated hardwood timber, with variations in preservative concentration having an insignificant effect. Over all conditions the probability of hardwood timber deterioration was 5 times that of the softwood. The results of this trial confirmed that timber stored closely stacked and under poorly ventilated conditions suffered a higher visible degrade, as expected for sapstain fungi. However, although preservatives effectively reduced visible degrade under all storage conditions and at all concentrations tested, selection of correct storage conditions was also an important part of minimising degrade.
J Snow, P Vinden, S M Read

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

Tentative method of testing wood preservatives against blue staining
1977 - IRG/WP 259
The blue stain of sawn wood is still a real problem in Poland. Although a preservative based on sodium orthophenylphenoxide has been introduced into sawmill practice, and the technology of wood protection developed with it, new information has been obtained concerning blue stain in wood material destined for export. In order to select new chemicals or to improve the effectiveness of the ones in current use it is necessary initially to carry out laboratory tests of the prepared chemicals to determine their efficiency.
E Tarocinski, O Lewandowski, M H Zielinski

The influence of previous anti-blue-stain preservative treatments on the fixation of CC in spruce
1997 - IRG/WP 97-30134
Freshly cut and kiln dried spruce boards were treated with 4 different anti-blue stain preservatives (ABP). After a period of 10 days allowing the samples to dry and fixate, the samples were treated with CC (chromium, copper formulation) using a vacuum pressure cycle. After impregnation the wood was steam fixed. A submersion leaching test showed differences in the leachable quantity of copper and chromium. When related to the retention of both salts after impregnation, no differences could be found between samples previously treated with anti-blue-stain preservatives and untreated samples. However, the retention of CC diminished significantly by application of quaternary ammonium compounds.
M Van der Zee, W J Homan

Characterisation of growth and stain of different groups of sapstain fungi on lodgepole pine
1999 - IRG/WP 99-10326
Canada is the world&apos;s largest exporter of softwood lumber. These softwood shipments are susceptible to a variety of wood-inhabiting fungi that can lead to sapstain discolouration, which in turn decrease the product value. Furthermore, the presence of these microorganisms may be unacceptable to the importing countries. The objective of this work is to assess the sapstaining capability and basic nutrition of thirty-four fungi isolates representing nine species that were isolated from sawmills across western Canada. The isolates were infected onto fresh lodgepole pine billets and assessed for staining ability, longitudinal growth, host-nutrient consumption, and host viability. The results indicated that the most aggressive saptain species on fresh logs was Ceratocystis coerulescens, followed consecutively by Leptographium spp, Ophiostoma minus, O. piliferum, O. piceae, Ophiostoma spp (D and E) and Aureobasidium pullulans. Preliminary HPLC analysis of soluble sugars indicated that mannose was the free monomer carbohydrate of choice for most of the staining fungi, followed by glucose. Arabinose and galactose were not well utilised. Gas chromatography of infected wood extracts that Leptographium sp. and C. coerulescens significantly reduced the triglyceride fraction.
C Fleet, C Breuil, A Uzunovic, A Byrne

Anti-stain field trials in British Columbia
1981 - IRG/WP 3174
Four alternative anti-sap stain chemicals were subjected to a four month field evaluation during the summer of 1980. The test, established at a Vancouver Island sawmill, was designed to evaluate the potential long-term effectiveness of sodium tribromophenate (Velsicol Ltd.), Biocom XX (Bramco Industries) containing methylene bis-thiocyanate, Woodbrite NTX (Van Waters & Rogers Ltd.) containing 3-iodo-2-propynyl-butyl carbamate and Mitrol 48 (Kenogard) containing guazatine acetate and quaternary ammonium chlorides, on hemfir and Douglas fir. Sodium tribromophenate was found to give surface protection equivalent to that of chlorophenate treated controls. Biocom XX was also effective, although the active ingredient came out of solution at the required treating solution concentration. Woodbrite NTX and Mitrol 48 were found to be ineffective on either species group under the test conditions.
D V Plackett

Blue stain in timber in service. Results of co-operative tests to compare different artificial weathering systems 1981-82
1983 - IRG/WP 2193
The paper describes results of the third phase of co-operative laboratory experiments comparing the effects of different artificial weathering systems on chemicals to control blue-stain in service. Atlas, Xenotest and Marr equipments are shown to give essentially the same results for 5 of the 6 chemicals tested.
A F Bravery, D J Dickinson

Rapport sur l'activité du CEN/TC 38
1983 - IRG/WP 2204
M Pottevin

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