Your search resulted in 620 documents. Displaying 25 entries per page.
Ten year field test with a copper-borate ground line treatment for poles
1993 - IRG/WP 93-30017
A wood preservative paste consisting of borax and copper naphthenate has been tested to determine its efficiency in protecting wood from decay fungi and insects. The paste was applied to polyethylene-backed wraps that were fastened to the below-ground portions of unseasoned southern pine pole stubs. After 4 years of exposure in Mississippi, the untreated control stubs were completely deteriorated. The below-grade portions of the treated stubs remained sound after nearly 6 years of exposure due to movement of copper and diffusion of the borate throughout the cross section. Borate and copper also moved vertically in the stubs and was present in sufficient amounts to protect sections of the stubs as high as 3 feet above grade. After 9 years of exposure, the below-grade portions of the treated stubs had limited areas of decay and no termite damage; the majority of the cross section remained sound. Wood analysis indicated that concentrations of borate in the sound areas were about 1/10 the estimated toxic threshold. A visual examination and push test indicated that the treated stubs continued to be protected at groundline after 10 years of exposure. It is hypothesized that the continued protection of the below-grade portions of the stubs against both decay fungi and subterranean termites is the result of copper-borate complexes that have formed in the wood.
T L Amburgey, M H Freeman
A Preliminary Report on the Properties of Engineered Wood Composite Panels Treated with Copper Naphthenate
2005 - IRG/WP 05-40294
This paper reports on our preliminary investigation of the properties of randomly oriented strandboard which had waterborne or powdered copper naphthenate (CuN) incorporated into the board during manufacture. When compared to zinc borate-treated controls (ZnB), the mechanical properties of strandboard (MOR, MOE, work-to-maximum load, internal bond strength) were not adversely affected by treatment with either form of copper naphthenate. In general, values for mechanical properties followed the trend untreated controls > waterborne CuN = powdered CuN > ZnB. Water absorption and dimensional properties followed a similar trend. This preliminary study suggests that CuN is a viable alternative treatment for engineered wood composites.
J W Kirkpatrick, H M Barnes
Evaluating the natural durability of native and tropical wood species against Reticulitermes flavip
2004 - IRG/WP 04-10539
Environmental pressures to eliminate arsenate from wood preservatives has resulted in voluntary removal of CCA for residential applications in the United States. A new generation of copper organic preservatives has been formulated to replace CCA for decking and in-ground applications but there is no guarantee that these preservatives represent a permanent solution to all related problems. Therefore, it is still necessary to evaluate alternative treatments, as well as naturally durable wood species, in order to be prepared for future changes in the field. In this study, six hardwoods and six softwoods have been evaluated for their ability to resist termite damage by Reticulitermes flavipes in a 4-week laboratory no-choice test. In addition, moderately resistant Douglas-fir and southern pine wood blocks were evaluated after treatment with copper borate, copper naphthanate, and N,N-naphthaloylhydroxylamine (NHA). Erisma, juniper, ipe and white-cedar were shown to be highly resistant. NHA protected Douglas-fir and southern pine as effectively as copper borate or copper naphthanate. These results suggest that some naturally durable wood species, both tropical and native, can inhibit R. flavipes as effectively as preservative treatment.
R A Arango, F Green III, K Hintz, R B Miller
Remedial ground-line treatment of CCA poles in service. Results of chemical and microbiological analyses 6 months after treatment
1986 - IRG/WP 3388
CCA-treated poles in service with incipient internal soft rot were remedially treated by inserting borate rods, brushing with a boron/glycol solution and injecting boric acid paste, copper/creosote paste or a commercial product (DFCK paste). The spread of active chemicals in the treated zone as well as the change in microflora have been studied with time. After six months chemicals had spread to most parts of the pole in the ground-line zone and the microflora had been changed - in some cases drastically. The test is still in progress. Chemical and microbiological analyses after 12, 28 and 60 months will be published at a later date.
B Henningsson, H Friis-Hansen, A Käärik, M-L Edlund
Field performance of novel antisapstain formulations
1997 - IRG/WP 97-30125
The effectiveness as antisapstain formulations of combinations of oxine copper (Cu-8), carbendazim, hexaconazole, cyproconazole, flusilazole, didecyldimethyl ammonium chloride (DDAC), an alkanolamine borate (SB), benzalkonium chloride (BAC), 2-n-octylisothiazolin -3-one (isothiazoline) and p-chlorophenyl-3-iodopropagilformal (CPIPF) was determined for freshly sawn, block-stacked radiata pine in three 18-week field trials: 1. Established in summer 1992 evaluating combinations of hexaconazole, carbendazim and DDAC. 2. Established in autumn/winter 1994 evaluating combinations of hexaconazole, carbendazim, DDAC, BAC and SB. 3. Established in autumn/winter 1995 evaluating combinations of triazoles, DDAC, Cu-8, carbendazim, CPIPF, isothiazoline and SB. Reference standards included: Cu-8; Cu-8 + carbendazim; IPBC + DDAC and TCMTB. In all tests, formulations containing carbendazim + hexaconazole + DDAC gave better protection for 12 and 18 weeks than most other experimental formulations and were equal to or better than commercial standards.
D R Eden, R N Wakeling, C M Chittenden, J G Van der Waals
The effect of pretreatments on the impregnation of air-dried sawn Belgian spruce
1988 - IRG/WP 3490
In general the impregnation of airdried spruce results in a variable treatment and limited penetration. This is the result of pit aspiration that occurs during drying of the spruce sapwood and heartwood. Spruce timber is becoming of greater importance in Belgium and hence research for better treatment of this vulnerable wood species is needed. Squared airdried timber of different dimensions were extracted from 10 winter-felled logs (Picea abies (L.) Karst) and impregnated with preservative used for constructional purposes. Partly the material was presteamed or waterlogged. Prior to the preservative treatment both groups were reconditioned to the same moisture content as the reference material (airdried). Retention and different penetration parameters showed better figures when only modifying the treating cycle rather than using a pretreatment. Both pretreatments seemed to have no positive effect on the treatability of airdried material. Increasing the strength of the initial vacuum parameters of the full-cell processes improved the degree and homogenity of the penetration of the preservative components.
J Van Acker, M Stevens
Diffusion modeling of inorganic wood preservative leaching in service
2005 - IRG/WP 05-50224-5
To evaluate the potential environmental and health implications of leaching of inorganic wood preservatives in service under different conditions, there is a need for a predictive model that provides estimates of the rate and extent of leaching over a wide range of product dimensions and exposure conditions. In this paper, we show that the leaching behavior of inorganic preservative components from wood in continuous water contact can be characterized by three easily measured parameters: total leachable component (Le) based on intensive leaching of fine ground material; amount of dissolved or dissociated component (Di) in water saturated wood; preservative component diffusion coefficients (Dt,l) in the transverse and longitudinal directions. Use of the applicable D and Di or Le in a diffusion model allows the prediction of total amount leached and emission rate at different times of exposure. Both D and Di increase somewhat with increasing ambient temperature. Laboratory determined parameters for alkaline copper quaternary (ACQ), copper azole (CA), chromated copper arsenate (CCA) and borate (DOT) wood preservatives are used to predict leaching rates from larger lumber samples. Preliminary comparisons of predicted leaching with measured leaching of larger samples in laboratory and natural rain exposure indicate that the approach is surprisingly effective at predicting leaching performance but some model refinements are needed for some components such as copper in CCA to account for the slow dissolving of a component of the preservative available for leaching.
L Waldron, P A Cooper, Y T Ung
Preservative treatment of green timber by soaking in ammoniacal copper borate
1984 - IRG/WP 3292
Freshly sawn boards of radiata pine sapwood were preservative treated by soaking in ammoniacal copper borate. Optimum schedules were obtained by partially seasoning the boards for one week prior to treatment. This aided the absorption of preservative and reduced the required soaking time to approximately 2 hours. Complete boron penetration was obtained after one week of block storage under cover and air drying. Copper penetration was more limited because of fixation of copper. The preservative treatment system should have particular application in the treatment of coconut timber destined for above-ground use but exposed to the weather.
P Vinden, A J McQuire
Upgrading the fungal resistance of OSB
1999 - IRG/WP 99-40138
There is a perception that oriented strand board (OSB) is less resistant to fungl than plywood under conditions of moderate exposure to moisture. Douglas fir-faced plywood (DFP) has been suggested as a benchmark for acceptable durability under such conditions. This project was initiated to determine the minimum level of low-toxicity chemical treatment needed to upgrade the fungal resistance of OSB, made from aspen, to equal that of DFP. Against a brown-rot fungus in a soil-block test, 0.2% zinc borate (ZB), added during manufacture, and subsequent spray treatment with 10 µg/cm2 oxine copper provided the required performance. Against a white-rot fungus 0.2% ZB alone was sufficient and between 0.1 and 0.2% may have been adequate. For resistance to mould in a humidity chamber, spray treatment of OSB with 10 µg/cm2 oxine copper provided equivalent performance to DFP. The recommended combination of treatments for moderate moisture exposure is 0.2% zinc borate and 10 µg/cm2 oxine copper.
P I Morris, J E Clark, D Minchin, R Wellwood
Copper borate for the protection of engineered wood products
2006 - IRG/WP 06-40334
Copper borate was evaluated for use in protecting oriented strand board (OSB) from mould, decay, and termites. Aspen OSB bonded with either phenolic or isocyanate resin was treated with several formulations of copper borate at various loadings from 0.26 to 4 percent by weight. These panels were then tested to determine the impact of the preservative on mechanical properties as well as resistance to fungal decay, mould, and Formosan termite attack. With proper resin selection, acceptable panels could be produced with both phenolic and isocyanate resin. The 10% copper hydroxide formulation of copper borate provided superior protection against mould, while all formulations tested gave adequate protection against fungal decay and Formosan termite attack. This paper summarizes over 5 years of research and the production of several hundred panels.
R Smart, W Wall
Laboratory evaluation of borate amine: Copper derivatives in wood for fungal decay
2010 - IRG/WP 10-30543
The aims of this study were to evaluate borate: amine: copper derivatives in wood for fungal decay protection as well as the permanence of copper and boron in wood. Wood treated with each of four derivatives of borate:amine:copper prevented fungal decay. Disodium tetraborate ecahydrate (Borax):amine:copper derivatives with retentions of 0.61 to 0.63% after water leaching prevented decay by Gloeophylum trabeum (Gt) and 0.64% by Trametes versicolor (Tv). Leaching did not decrease decay resistance to both Gt and Tv. Disodium octaborate tetrahydrate(DOT):amine:copper derivatives with retentions of 1.14 to 2.93% after water leaching prevented decay by Gt and 0.54 to 1.19 % by Tv. Leaching decreased decay resistance to Gt but not to Tv. Higher copper and boron in disodium borax:amine:copper derivatives contributed to more decay resistance to Gt and Tv than that of DOT:amine:copper derivatives as evidenced by elemental analysis. Infrared spectra (IR ) of wood treated with 5% borate: amine: copper derivatives after water leaching showed that increased absorption at 1632-1635 cm-1 compared with the control. The increased absorption at 1632-1635 cm-1 was partly attributable to carbonyl of copper carboxylates from oxidation of hemiacetals of hemicelluloses and cellulose by copper (II) ions, and carbonyls of copper (II) quinone methides by oxidation of guaicyls by copper (II) ions. It was also partly attributable to carbonyls of copper carboxylates from hemicelluloses and phenolates from lignin through ion exchange reactions. The above oxidation and ion exchange reactions of copper with wood components may account for their efficacy and long term performance.
Mold Control for Treated Lumber in Block-Stack Storage Conditions
2012 - IRG/WP 12-30588
The mold development and control for freshly treated and block-stacked wood have been evaluated using a green house mold testing method. The results for the mold resistance of several commonly used water boron preservative treatment systems, such as ACQ, Copper Azole, and borates with and without inclusion of mold inhibitors are presented. The data suggest that the different preservative treatment systems have their own very different mold resistance characteristics. The addition of mold inhibitor or in some cases combination of mold inhibitors or additives can provide effective control of mold development. The results also suggest that the green house mold test method reported here can simulate the worst case scenario confronted by treated wood in block-stack situations during storage, retailing and installation.
L Jin, P Walcheski, A Preston
Termite resistance of copper-based preservative supplemented aspen strandboards
2012 - IRG/WP 12-30594
Termite resistance of aspen strandboards treated with various copper-based preservative systems was evaluated in field exposure tests. Five copper-based chemicals or zinc borate were blended into aspen furnish at three retention levels prior to pressing. Tebuconazole or 4,5-dichloro-2-N-octyl-4-isothiazolin-3-one (DCOI) were added as co-biocides to selected copper-based treatments. Sections from the panels were exposed to a colony of Formosan termite (Coptotermes formosanus) in an American Wood Protection Association Standard E21 test. Incorporating some combinations of copper-based preservative systems with organic co-biocides markedly improved the termite resistance of aspen oriented strandboard.
J J Morrell, C Vidrine, A Preston, L Jin
Cost effective extension of service life of bridge tie (sleepers) - Effectively applying borate during Boulton conditioning and treatment with copper naphthenate
2014 - IRG/WP 14-30637
Current longevity of creosote treated wooden bridge ties in the South Eastern US is about 15 to 25 years, which is well below of the average service life of 33-50 years of railroad ties. Such short service life increases costs associated with maintenance of railroads including bridge down time for tie replacement as well as the cost for the new ties themselves. Because of this, many railroads are seeking non-wood alternative ties, even at vastly elevated initial cost. The objective of the study was to see if it is possible to apply borate as part of a dual treatment with copper naphthenate, in order to increase the service life of wooden bridge timbers at minimal additional cost. Green hardwood ties were ported, borate treated, and then Boulton treated with copper naphthenate at a commercial tie treatment plant in Pennsylvania. Diffusion of borate within the wood appeared to be significantly enhanced by the elevated temperature and steam generated during the Boulton cycle and subsequent pressure treatment with copper naphthenate. The achieved retention and penetration of borate and copper naphthenate met AWPA standard retentions and AREMA guidelines. The longevity of ties should be significantly increased by protecting the heartwood with disodium octaborate tetrahydrate (DOT) and the sapwood with copper naphthenate. The results suggested that hardwood ties can be successfully treated with borate during a Boulton cycle and should allow the continued effective use of sustainable wooden bridge timbers.
J D Lloyd, T Chambers, J-W Kim
Borate Redistribution in Glulam in an Above Ground Field Test
2014 - IRG/WP 14-30652
Researchers have refocused on the use of boratesin the wood protection industry in the last two decades due to their broad spectrum effectiveness against fungi and insects, and favourable environmental characteristics. This study was designed to determine borate distribution in a limited number of samples from a large field test of composites protected by a combination of coating and borate treatment by two processes.The intended application of these products was exterior components of buildings with considerable protection by design, but the test method was designed to be a much more severe exposure. A variety of structural composites had been machined into ɣ-joint test samples, then borate-treated by two methods: a surface-applied penetrating process, and a dip treatment with borate/glycol plus insertion of copper/borate rods.After application of the coating the test samples had been installed in a long-term above-ground outdoor weathering trial at FPInnovations’ Maple Ridge, British Columbia test site. After seven years of exposure, selected glulam beams of black spruce, white spruce, and Douglas-fir samples were destructively sampled and analyzed for borate retention and penetration, with results compared to unexposed material.Results showed that borateshad migrated from the surface of exposed samples to inside the wood, as deep as 50 mm, and in many samples were present in concentrations that would be sufficient to prevent fungal decay.
P I Morris, A Temiz, J Ingram
Borate and Copper Naphthenate Dual Treatment of Bridge Timbers-Borate movement over time
2017 - IRG/WP 17-40795
Preservative treated wooden bridge ties in the South Eastern USA have a service life of about 15 to 20 years, which falls well below the average service life of 40 years of railroad cross ties (sleepers). It has been shown that cross tie life is significantly extended using borate dual treatment and this is now commercialized in bridge timbers using borate inserts. In previous research, it was demonstrated that distribution of disodium octaborate tetrahydrate (DOT) within the wooden bridge ties was dramatically accelerated during Boulton treatment. The objective of this study was to determine how much diffusion of borate inside the bridge tie after initial treatment occurred over time. Green hardwood bridge ties were ported, borate treated, and then Boulton seasoned and treated with copper naphthenate at a commercial tie treatment plant in Pennsylvania, U.S.A. Retention and location of borate within the wood was tested at 3, 14 and 40 weeks after the treatment. It appeared that borate continued to diffuse inside of the tie and would likely treat and protect a significant volume of the heartwood over time and thus increase bridge tie life in a similar way to crossties.
J-W Kim, J D Lloyd
Dual Borate and Copper Naphthenate Treatment of Bridge Timbers:- Potential Performance Enhancements and Cost Savings
2017 - IRG/WP 17-40797
Dual treatment technology combining diffusible preservatives with oil borne preservatives, widely used for crossties in the USA, has now also been commercialized with bridge ties/timbers. In order to understand the implications of these changes, the historic service life of creosote treated bridge timbers in northern and southeastern USA were considered as well as field test data for both creosote and copper naphthenate. These were used to estimate potential future service life. Estimates on life expectancy with added borates were also made from published data on performance. Cost benefit analysis based on creosote and copper naphthenate costs as well as assumptions made from field test efficacy data suggest cost savings of up to $20 per timber per year of additional service. Service life extension and the resulting cost savings could be achieved in a number of ways: change preservative from creosote to copper naphthenate; increase active ingredient retention; and/or add dual treatment protection. A preservative change from creosote to copper napthenate would be the simplest and lowest cost way of increasing service life of bridge timbers, with potential savings to both treater and railroad. An increase in copper retention could also give significant life extension, could be carried out at little additional cost and without increasing bleeding. The addition of borate to protect the heartwood also provides significant assumed increase bridge tie life, and can be used with either creosote or copper naphthenate treatments.
J Lloyd, C Brischke, R Bennett, A Taylor
Economic and Alternative Preservative Research with an Overview of its Impact on the Dynamics of Wood Tie Markets and Railroads
2019 - IRG/WP 19-30751
This presentation will discuss the Railway Tie Association’s (RTA) efforts in economic research for the North American wood tie industry, along with decades-long research into improving wood preservation processes and its resulting economic impact for railroads. Ongoing research is continuing to expand the knowledge-base by comparing existing standard creosote (C) and borate-creosote (B-C) dual-treatments with each other and with other potential alternatives. This is particularly important research for tie species which are refractory with hard to treat heartwood. The economic value of commercializing dual-treatment processes, and the continuing advancement of other wood preservation technologies such as copper naphthenate (CuN) and borate-copper naphthenate (B-CuN) suggest both a shift in marketplace dynamics as well as massive long-term savings. Some of these benefits may be now manifesting as a secular change in the marketplace. Other economic considerations which play a role in current and future marketplace dynamics and robust tie demand are also explored.
J C Gauntt
Comparative response of Reticulitermes flavipes and Coptotermes formosanus to borate soil treatments
1991 - IRG/WP 1486
Eastern (Reticulitermes flavipes [Kollarl]) and Formosan (Coptotermes formosanus Shiraki) subterranean termite workers (Isoptera: Rhinotermitidae) were exposed to borate-treated sand in an indirect exposure tunneling assay in the laboratory. In the ten day assay period, both termite species readily penetrated sand containing 5000, 10000, or 15000 ppm (wt. of compound / wt. of sand) disodium octaborate tetrahydrate (Tim-BorÒ) or zinc borate (Firebrake ZB-FineÒ). With Reticulitermes flavipes, significant mortality (85-93%) resulted from workers tunneling through sand treated with 5000 ppm disodium octaborate tetrahydrate (higher concentrations were also effective), or 15000 ppm zinc borate. Responses of Coptotermes formosanus workers were lesser and more variable, with only concentrations of 10000 and 15000 ppm zinc borate resulting in mortality 70-89%) significantly different from that in the control groups. These results suggest that differences between these two species in tunneling behavior may reduce exposure of Coptotermes formosanus to the borate-treated sand.
J K Grace
Preliminary study of the fungicidal and structural variability in copper naphthenates and naphthenic acids
1996 - IRG/WP 96-30114
Copper naphthenates, an oil-borne wood preservative listed by the American Wood-Preservers' Association (AWPA), is manufactured by complexing copper(II) with naphthenic acids. Prior to AWPA listing as a wood preservative, field experiments showed that copper naphthenates generally had good stability and were active against wood-destroying organisms. Recently, however, there have been reports of some copper naphthenate-treated poles rapidly failing. One possible explanation for the varying effectiveness could be that the structure, and resulting biological activity, of the naphthenic acids used to make copper naphthenate may vary. To test this hypothesis several naphthenic acids and copper naphenates were obtained and their fungicidal activity against three wood-destroying fungi measured. In addition, the chemical structure of the naphthenic acids were examined by proton- and carbon- NMR. Different activities were observed, especially against a copper-tolerant fungus. Some apparent correlations were seen between the fungicidal activity and chemical structures for the few samples studied.
T Schultz, D D Nicholas, L L Ingram Jr, T H Fisher
Sequestration of copper ions by the extracellular mucilaginous material (ECMM) of two wood rotting basidiomycetes
2004 - IRG/WP 04-10533
The radial growth rate of colonies originating from either whole or ECMM-free inocula of Coriolus versicolor was investigated. The presence of ECMM allowed colonies to maintain higher growth rates than those form ECMM-free inocula up to 2 mM CuSO4 in the medium. The ECMM of C. versicolor and G. trabeum was able to reduce the diffusion of copper ions in solution. The ‘raw’ ECMM of both fungi had a greater ability to reduce the diffusion of copper ions than ECMM which had been subject to dialysis to remove soluble, low molecular weight components. The ‘insoluble’ fraction of ECMM for both species was more effective than the ‘soluble’ fraction at reducing the diffusion of copper ions. It is concluded that ECMM confers some protection to hyphae against the toxic effects of copper ions on growth in vivo and that this due to the binding of copper ions to both the polysaccharide and to low molecular weight components of the ECMM
D Vesentini, D J Dickinson, R J Murphy
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
Types of decay observed in CCA-treated pine posts in horticultural situations in New Zealand
1984 - IRG/WP 1226
The few reported failures of 11-12-year-old horticultural posts in New Zealand in 1982 were caused by brown-rot. A subsequent survey of CCA-treated posts in all the major horticultural areas has revealed decay of many posts. A microscopic examination of these posts has shown decay by brown-rot, white-rot, soft-rot and bacteria. Several types of bacterial decay have been observed.
J A Drysdale, M E Hedley
An investigation of the effects of pre-steaming on the treatment of sawn spruce timber with Celcure A, a copper-chrome-arsenic preservative
1981 - IRG/WP 3150
Difficulties in the treatment of spruce using standard vacuum/pressure techniques with both water-borne and organic solvent preservatives are well known. We have evaluated the influence of steaming on treatability with a waterborne CCA preservative.
C R Coggins
International collaborative laboratory comparison of two wood preservatives against subterranean termites: Third update and first report
1996 - IRG/WP 96-10174
At the 24th annual meeting of IRG in Orlando, USA, in May 1993 an international subterranean termite laboratory bioassay to compare the various preferred termite protocols used by IRG termitologists was initiated. The author was nominated to co-ordinate this comparative laboratory evaluation of two wood preservatives, copper-chrome-arsenic (CCA) and copper naphthenate (Cu-Na) against the subterranean termites used as test termites in Australia, France, Japan, Thailand, United Kingdom and the Unites States of America. Solutions of these two wood preservatives were prepared and impregnated into Pinus radiata wood blocks to obtain loading of 0.0, 0.5, 1.0, 2.0 and 4.0 kg/m³ respectively. All preservative treatments were carried out at the Division of Forestry and Forest Products in Melbourne. The treated specimens were dispatched to the participating researchers who subjected these specimens to attack by their test termite species, and have now returned the specimens to Melbourne. This paper reports the amount of wood consumed and the mean mass loss (%) on both treated and untreated wood blocks by the termites in the various laboratory bioassays.
J R J French