Your search resulted in 344 documents. Displaying 25 entries per page.
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.
Fire resistance of Alder wood treated with some chemicals.
Part II. Effect of Other Chemicals on the Combustion Properties
2002 - IRG/WP 02-40235
Samples from alder wood (Alnus glutinosa (L.) Gaertn. subsp. barbata (C.A.Mey) Yalt.) were impregnated according to ASTM D 1413-88 with boron compounds (boric acid, borax, sodium perborate), vinyl monomers (styrene, methyl methacrylate), Tanalith-CBC, Phosphoric acid, Vacsol, Immersol, Polyethylene glycole (PEG-400) and their mixed solutions of chemicals in order to determine their combustion properties. The results indicated that inorganic boron compounds with aqueous solutions were very effective as fire retardant and reduced burning of some vinyl monomers at some extent such as styrene and methylmetacrylate when used as a secondary treatment chemical polimerized later on wood structure and phosphoric acid was also showed fire-reterdancy. Further studies are suggested on boron-vinyl monomers, and boric acid+borax with different concentrations by physical and chemical interactions in terms of fire reterdancy.
A Temiz, Ü C Yildiz
Preliminary note on the fungal problem of rubber wood
1983 - IRG/WP 3246
Susceptibility of rubber wood to fungal attack limits its wider utilisation. Fungal problems encountered in treating rubber wood with boron compounds by diffusion process have been discussed. Sodium pentachlorophenoxide and 2-thiocyanomethylthio benzothioazole (TCMTB) were investigated for possible control of fungal growth during diffusion storage and their performance has been reported.
Evaluation of an alkyl ammonium compound as a fungicide to control sapstain and mould during diffusion storage
1984 - IRG/WP 3282
An alkyl ammonium compound ('Akzo' ES 255) was evaluated for its effectiveness against mould and sapstain during diffusion storage of boron-treated rubber wood. Though ES 255 at 1.0% concentration was effective against mould (71%) and sapstain (89%) it is less satisfactory compared to 0.5% sodium pentachlorophenoxide against mould (92%) and sapstain (98%).
Remedial ground-line treatment of CCA poles in service. A final report after 60 months' testing
1989 - IRG/WP 3534
Remedial treatment of CCA treated utility poles of Pinus sylvestris with incipient decay was carried out in 1983 and the results of chemical and microbiological analyses 6 months after treatment were reported in Document No: IRG/WP/3388 while microbiological studies 12 and 28 months after treatment as well as chemical analyses of poles treated with boron rods or boric acid paste 28 months after treatment were reported in Document No: IRG/WP/3481. 60 months after the treatment a final study was carried out on the remaining two poles left from each treatment. The study included isolations of fungi as well as chemical analyses of poles treated with boron rods, boric acid paste and borate/glycol.
B Henningsson, H Friis-Hansen, A Käärik, M-L Edlund
Preservative treatment of different thatching materials for low cost housing
1999 - IRG/WP 99-40144
Preservative treatment were made in seven different roofing materials with Copper-Chrome-Boron (CCB) at different concentration by soaking process. These were paddy straw, wheat straw, jute stick, sungrass, ulu grass, sugercane leaf and Nipa fruticans. It was observed that retention of preservative chemicals varies from species to species at the same concentration. From the service test it was observed that by using low concentrated solution at minimum immersion period, durability of the thatching materials can increased which is economically acceptable and enviromnental pollution is also minimized.
K Akhter, M Younusuzzaman, M H Chowdhury
Economical schedule for boron treatment of rubber wood: Pilot plant investigations
1993 - IRG/WP 93-40002
An economical treatment schedule (15 minutes initial vacuum of 85 kPa; 15 minutes pressure of 1000 kPa; 5 minutes final vacuum of 85 kPa) was arrived at for treating air-dried rubber wood (Hevea brasiliensis) in a pilot plant cylinder. Treating with 3% BAE (boric acid equivalent) solution resulted in a dry salt retention of 13.1 kg/m³. Also, the study showed that green rubber wood can be treated to required chemical retention level by employing the above treatment schedule and by increasing the concentration of the treatment solution to 6% BAE.
R Gnanaharan, T K Dhamodaran
Biological Performance of Boron-based Chemicals Treated Wood Composites
2009 - IRG/WP 09-40464
In this study, the biological performance of wood-based composites panels treated with boron containing chemicals against to a fungus was determined. Boric acid, borax, zinc borate and agricultural borate (Tarım-bor™), developed and patented by National Boron Research Institute, were mixed with wood chips or fibers and then particleboard, medium strand board and middle density fiberboard were produced. The decay tests of these wood composites were done according to the soil-block test. Among the boron compounds, zinc borate demonstrated better resistance against to C. puteana fungus than other boron compounds used in this study. According to the durability classification, MDF was better than particleboard and MSB.
Ü C Yıldız, H Kalaycıoğlu, S Yıldız, A Temiz, E Tomak Dizman, A Çavdar Dönmez
Design, synthesis, characterisation and effectiveness of ‘Locked-in-Boron’ chemicals for H3.2 level of wood protection
2011 - IRG/WP 11-30577
Boratrane molecules with five-membered and six-membered molecular ring systems, and with various ring substituents were synthesised, characterised and formulated for wood treatment for accelerated laboratory bioassays using wood decay fungi as test organisms. Six-membered ring boratranes showed lower efficacy in laboratory assays than five-membered ring boratranes. One alkyl-substituted boratrane with a five-membered ring molecular structure was used in a 10-year natural hazard exposure test using lap-joint specimens treated with three boratrane concentrations. The half-life for boric acid controlled release for wood treated with the boratrane at a nominal 0.1% boric acid equivalent (bae) was approximately 4 years, while that for a nominal 1% bae was approximately 7 years, compared with a half-life of 10 months for conventional boric acid/borate wood treatment.
R Franich, H Kroese, S Gallagher, S Hill, B Kelly, G Billett, R Meder, W Rae
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
Aspects of diffusion of boron through wood
1984 - IRG/WP 3298
Boron compounds have been shown to be toxic to a wide range of wood destroying insects and fungi. They are cheap, have low mammalian toxicity and their application in the treatment of wood does not demand specialized equipment. These attributes make them specially attractive to developing countries. Currently, however, little is known about the mechanism of diffusion of boron through wood. Effective treatment with boron preservatives requires good understanding of how the preservatives diffuse through wood. This paper presents a research proposal with the overall objective of determining the relative importance of structural wood components in determining diffusion rates.
Utilization of curcumin for detection of presence of boron in wood
1982 - IRG/WP 3191
It has been shown that curcumin is not a reliable reagent for detecting boron in wood that has been attacked by fungi
Strength loss associated with steam conditioning and boron treatment of radiata pine framing
1987 - IRG/WP 3438
The combined effect of included defects and wood moisture content on the strength loss of second rotation radiata pine framing following conventional steam conditioning is investigated. The green Modulus of Elasticity (MOE) is reduced by approximately 13% after steaming. When dried after steaming, however, neither the MOE nor MOR is significantly different from unsteamed dried controls.
M J Collins, P Vinden
Synergistic effect of boron on Streptomyces rimosus metabolites in preventing conidial germination of sapstain and mold fungi
1992 - IRG/WP 92-1565
We evaluated the synergistic effect of boron (4% BAE solution of Tim-Bor or 4% boric acid) on Streptomyces rimosus metabolites in preventing spore germination of sapstain and mold fungi using plate bioassay, Southern yellow pine and sweetgum block tests, and green pine log sections: sapstain -- Ceratocystis coerulescens, Ceratocystis minor, and Aureobasidum pullulans; mold fungi -- Aspergillus niger, Penicillium spp, and Trichoderma spp. Inhibition of spore germination in plate bioassay by metabolites with boron was more effective than without added boron. Treatment of wood samples with the mixture of boron and unconcentrated metabolites also resulted in the synergistic effect and completely inhibited spore germination of sapstain and mold fungi.
S C Croan, T L Highley
Insect resistance of preservative treated tropical plywood against Lyctus
1990 - IRG/WP 1453
Seven plywood types composed of tropical wood species, vulnerable to Lyctus, were treated with various commercial water-borne and oil-borne preservatives. A wide range of preservative retentions was obtained by treating boards with dip treatment, steeping, double-vacuum and vacuum-pressure impregnations. Selected samples were subsequently tested for their insect resistance against Lyctus africanus during 6 to 8 months according to European Standard EN 20. All control samples were attacked, except one Obeche plywood exhibiting only 50% attack. Water-borne preservative solutions containing arsenic, boron or fluoride could not prevent attack at common retention levels for interior use e.g. lower than 5 kg/m³. Quaternary ammonium compounds showed no insecticidal efficiency, up to 3 kg/m³. TCMTB at 1.5-1.7 kg/m³ proved to be able to reduce slightly the susceptibility for insect attack. Organic insecticides gave the best results, with nearly no attack for plywood treated with lindane or cypermethrin. In spite of a preservative uptake of 25 to 30 kg/m³, endosulfan only could reduce attack by 50%. Protection by permethrin at 0.1% a.i. required a retention of 28 kg/m³. Besides the fact that variability in wood species and composition of the plywood are leading to different retention levels, variation in penetration and distribution of a.i., and as a consequence to a different insect resistance of the impregnated boards, some poor results were directly related to inadequate insecticidal activity and/or concentration of a.i. in some commercial formulations for Lyctus control.
J Van Acker, M Stevens, M Pallaske
Non-pressure treatability of plywood by CCA, CCB and boron
2005 - IRG/WP 05-40295
Study on diffusibility and absorbability of CCA, CCB and boric acid in 3 mm thick 3-ply hardwood plywood at water saturated and air-dry conditions and dipped at same concentration (5%) and same duration of time (12 hours) revealed complete diffusion of all the preservatives at water saturated condition. Only the CCA-C was found absorbed by the plywood at air-dry condition. The rate of absorption and diffusion of CCA-C was found about 4.5 times higher than CCB and boric acid.
A K Lahiry
Leaching of the new boron based biocide from coated wood
2001 - IRG/WP 01-30267
We investigated leachability of the new boron based biocide - a complex of an amine and boric acid - from vacuum impregnated spruce wood samples. It was determined by the standard ENV 1250-2 procedure that the new biocide is susceptible to leaching so from the water borne as well as from the ethanol borne boron containing preservative treated wood. Leaching may be retarded by application of surface coatings. The ability of a surface finish to prevent leaching is correlated to its water vapour permeability.
M Petric, M Pavlic, F Cadez
The evaluation of synergistic effects of chemicals on fungicidal efficacy in crossed-paper tests
1991 - IRG/WP 2383
The mixing effects of wood preservatives were evaluated using the crossed-paper technique. Two filter paper strips (0.7 x 8 cm²) were treated by soaking with different chemicals [fungicides, a termiticide (chlorpyrifos or phoxim), a surface-active agent, a synergistic agent, and a stabilizer], and placed at right angles to each other on a fully grown mycelial mat of a test fungus in a Petri dish. When the four organoiodine fungicides were incorporated with chlorpyrifos or surface active agent, only 3-iodo-2-propynyl butyl carbamate (IPBC) showed the desirable synergistic effect against every wood-decaying fungus tested. Other fungicides did not always tend to produce the synergistic effect with the addition of a surface active agent. 4-Chlorophenyl-3-iodopropargyl formal (IF-1000) appeared to indicate an undesirable antagonistic effect when mixed with either chlorpyrifos or a surface active agent. 3-Bromo-2, 3 diiodo-2-propenylethyl carbamate (EBIP) did not show any synergistic action by mixing with chlorpyrifos and/or a surface active agent, although the fungicidal enhancement was induced satisfactorily by mixing the fungicide with chlorpyrifos, a stabilizer and/or a synergistic agent, especially against Tyromyces palustris and Coriolus versicolor. Similarity of the results obtained in the present investigation and in the previous laboratory decay tests leads to the conclusion that the crossed-paper technique is suitable for the evaluation of the mixing effect of chemicals on fungicidal efficacy.
Dong-heub Lee, K Tsunoda, M Takahashi
Programme section 3, Wood protecting chemicals
1997 - IRG/WP 97-30159
Depletion of boron and copper from CCB treated test specimens using different leaching protocols
2004 - IRG/WP 04-50208
The objective of this study was to measure the depletion of inorganic wood preservative components regarding the proposed OECD guideline "Estimation of emissions from preservative-treated wood to the environment: laboratory method for wooden commodities exposed in the use class 4 and 5" as part of the project "Investigations concerning the influence of test parameters on the release of biocidal actives from treated timber in leaching tests". Pine sapwood specimens (50x10x150) were pressure impregnated with CCB according to European Use Class 4. Before leaching all samples were stores 4 weeks for fixation. In addition leaching tests were performed according to the European Standard EN 84 by means of EN 113 blocks. Parallel investigations were carried out between two laboratories to assess the repeatability and comparability of the methods. The results of chemical analysis of leachates taken at different time intervals show that similar depletion rates were determined for copper and boron independent on the leaching protocol used. However, the loss of copper as well as chromium in short term dipping experiments was often lower than the detection limit. Furthermore it can be stated that the difference between parallels was higher for the results which were obtained for the OECD guideline that EN 84. A comparison of both laboratory results indicate that a quite good repeatability is given in case of the CCB treated material.
E Melcher, R-D Peek, U Schoknecht, R Wegner
In search of alternative antisapstain chemicals for use in Papua New Guinea
1988 - IRG/WP 3472
The paper presents results of antisapstain field trials from three locations in Papua New Guinea as part of the Research Centre's programme to find suitable antisapstains to replace the hazardous sodium pentachlorophenate. Effectiveness of seven tested chemicals varied between indigenous pines (Araucaria cunninghamii, Araucaria husteinii) and white coloured hardwoods (Alstonia scholaris, Pterocymbium beccarii) but not between sites. The indigenous pines required lower chemical concentration for same level and period of protection than white coloured hardwoods like amberoi and white cheesewood. Period of protection ranged from four weeks to a maximum of 16 weeks depending on chemical concentration and species of timber. Potential chemicals recommended for use as antisapstain include Celbrite T, Busan 1009, Penacide and Woodguard E.S. and Woodguard E.C.
CCA modifications and their effect on soft rot in hardwoods
1982 - IRG/WP 3201
Decay tests were carried out on wood samples treated with three waterborne compounds all identical in composition but applied in different forms. There were significant differences in the effectiveness of the treatments particularly as regards the control of soft rot.
S M Gray, D J Dickinson
The long-term performance of boron treated joinery in service - A case study
2000 - IRG/WP 00-20208
Joinery treated with borates 23 years ago and in service in residential flats was surveyed and analysed for boron content. The levels of boron still present were sufficient to prevent decay. None of the windows surveyed showed any decay despite the fact that moisture and sapwood contents were conducive to decay.
D J Dickinson, R J Murphy
Laboratory evaluation of chemicals as termiticides
1986 - IRG/WP 1293
Laboratory procedures are described for screening chemicals against subterranean termites. Fast-acting compounds with persistent termiticidal activity are identified in tests using a soil substrate, and slower-acting bait toxicants are evaluated in a series of tests using cellulose substrates.
S C Jones
Commercially available anti-sapstain chemicals in New Zealand - An update
1987 - IRG/WP 3416
Six anti-sapstain chemicals or mixtures (NaPCP plus borax, Haipen 5F, Mitrol PQ375, Busan 1009, Protek S, Pinefol 50W) are available as commercial treatments in New Zealand. A further two (Hylite 20F and Isothon-35) have shown potential in field and mill trials and will be available for use. A number of other formulations are under evaluation.
J A Drysdale