Resistance to fungal decay of paraffin wax emulsion/copper azole compound system treated wood

Treated wood timbers employed in ground contact are often installed with a cement collar to firmly fix the structural wood post in place. Few prior studies have determined the effect of concrete on decay efficacy on treated wood, however. Treated wood nominal 4 × 4 posts were installed at four locations, with the upper ground-contact portion of each post encased in concrete, and the samples removed at various times for pH measurements. The wood alkalinity quickly increased at all four sites for the portion of the treated wood in concrete contact compared to the wood in ground contact without concrete. In laboratory decay tests employing three decay fungi, untreated wood which was first exposed or unexposed to concrete had no consistent difference in decay susceptibility. For wood treated with three different commercial copper/organic systems, cement exposure had no effect on wood treated with an amine copper azole system, while treatment with amine copper quat showed a statistically significant fungal efficacy enhancement for cement-exposed samples with both copper-tolerant fungi. Conversely, with a micronized copper azole preservative, cement exposure resulted in reduced fungal efficacy compared to treated samples which were not cement-exposed for all three decay fungi.

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Counter-current acid leaching process for copper azole treated wood waste

Environmental Technology ◽

10.1080/09593330.2012.660648 ◽

2012 ◽

Vol 33 (18) ◽

pp. 2111-2118 ◽

Cited By ~ 5

Author(s):

Amélie Janin ◽

Pauline Riche ◽

Jean-François Blais ◽

Guy Mercier ◽

Paul Cooper ◽

...

Keyword(s):

Acid Leaching ◽

Treated Wood ◽

Wood Waste ◽

Leaching Process ◽

Copper Azole ◽

Counter Current

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Prediction of long-term leaching potential of preservative-treated wood by diffusion modeling

Holzforschung ◽

10.1515/hf.2005.095 ◽

2005 ◽

Vol 59 (5) ◽

pp. 581-588 ◽

Cited By ~ 14

Author(s):

Levi Waldron ◽

Paul A. Cooper ◽

Tony Y. Ung

Keyword(s):

Diffusion Coefficient ◽

Treated Wood ◽

Free Water ◽

Wood Preservative ◽

Copper Component ◽

Equilibrium Dissociation ◽

Disodium Octaborate Tetrahydrate ◽

Alkaline Copper Quaternary ◽

Copper Azole ◽

Copper Amine

Abstract An approach to modeling leaching and leaching impacts of preservative components from treated wood is presented based on three simple laboratory determinations: the amount of preservative component available for leaching (Le), equilibrium dissociation of preservative into free water in wood (Di) and diffusion coefficients for component leaching in different wood directions (D). In this study, the following inorganic wood preservative systems were investigated: chromated copper arsenate (CCA), the copper component of copper azole (CA) and alkaline copper quaternary (ACQ), and boron in disodium octaborate tetrahydrate (DOT). Aggressive leaching of finely ground wood showed that amounts of preservative compounds available for leaching were highest for borates, followed by copper in copper amine systems and arsenic in CCA, copper in CCA and chromium in CCA. The equilibrium dissociation or solubility of components in free water in the wood was much higher for borates and copper amine, followed by copper and arsenic in CCA and chromium in CCA. Use of the applicable diffusion coefficient (D) and Di or Le values in a diffusion model allows the prediction of total amount leached and emission or flux rate at different times of exposure for products with different dimensions and geometries. The approach was tested and generally validated through application of the model to results of laboratory water spray leaching of full-size lumber samples. The approach explains the rapid leaching of boron compounds (large diffusion coefficient and high initial dissociated concentration) compared to other preservative components and predicts that ACQ will have higher initial leaching rates compared to CCA and CA, but the latter preservatives will continue to leach copper at a measurable rate for a much longer time. The practical implications and limitations of the approach are discussed.

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In vitro bioaccessibility of copper azole following simulated dermal transfer from pressure-treated wood

The Science of The Total Environment ◽

10.1016/j.scitotenv.2017.03.227 ◽

2017 ◽

Vol 598 ◽

pp. 413-420 ◽

Cited By ~ 1

Author(s):

Jennifer L. Griggs ◽

Kim R. Rogers ◽

Clay Nelson ◽

Todd Luxton ◽

William E. Platten ◽

...

Keyword(s):

Treated Wood ◽

In Vitro Bioaccessibility ◽

Copper Azole

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Comparative Aboveground Performance of Pressure-Treated Copper Azole with Alternative Wood Protection Systems under Subtropical Conditions

Forest Products Journal ◽

10.13073/fpj-d-20-00023 ◽

2020 ◽

Vol 70 (3) ◽

pp. 335-339

Author(s):

Matthew J. Konkler ◽

Gerald Presley ◽

Jeffrey J. Morrell

Keyword(s):

Surface Treatments ◽

Pressure Treatment ◽

Fungal Decay ◽

Wood Protection ◽

Rigorous Testing ◽

Protection Systems ◽

Termite Attack ◽

Silica Treatment ◽

Copper Azole ◽

Insect Attack

Abstract The performance of several wood surface treatments as well as a silica treatment claiming to provide protection against fungal decay and termite attack in aboveground applications were examined in termite, ground proximity, and sandwich tests at a subtropical site near Hilo, Hawaii. In general, the surface treatments performed similarly to untreated controls and provided little or no protection against fungal or insect attack. The silicate treatment provided some termite and decay protection, but fungal decay resulted in rapid declines in condition after 50 to 54 months of exposure. Copper azole–treated lumber provided the best performance against both termites and fungal attack, illustrating the benefits of pressure treatment over surface treatments in high-decay-hazard environments. These results also illustrate the importance of rigorous testing and standardization protocols for any product that makes durability claims before it enters the market to ensure that it will perform as expected.

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Biological performance of copper azole-treated wood and wood-based composites

Holzforschung ◽

10.1515/hf.2010.039 ◽

2010 ◽

Vol 64 (3) ◽

Cited By ~ 7

Author(s):

Cihat Tascioglu ◽

Kunio Tsunoda

Keyword(s):

Oriented Strand Board ◽

Medium Density Fiberboard ◽

Treated Wood ◽

Coptotermes Formosanus ◽

White Rot ◽

White Rot Fungus ◽

Vacuum Impregnation ◽

Decay Fungi ◽

Biological Resistance ◽

Copper Azole

Abstract Vacuum-impregnation with copper azole was applied as a post-treatment to five commercially available wood-based composites with thicknesses of approximately 12 mm, such as softwood plywood (SWP), hardwood plywood (HWP), medium density fiberboard (MDF), oriented strand board (OSB), and particleboard (PB). Untreated and treated composites were tested for their resistance to decay fungi (brown rot fungus Fomitopsis palustris and white rot fungus Trametes versicolor) and the subterranean termite Coptotermes formosanus by Japanese standardized laboratory test methods. Untreated MDF was highly resistant to both biological attacks and seemed to require no preservative treatment under less hazardous conditions, i.e., under protected and above-ground applications, with possible occasional wetting. PB was ranked second, and needed further protection only against C. formosanus. Copper azole did not adequately protect SWP from F. palustris and termite. OSB was not protected either against F. palustris and T. versicolor even at a concentration level of 1 kg copper azole per m3 in contrary to blocks of Cryptomeria japonica sapwood, which was protected at these concentration levels. The biological resistance of HWP was reasonably improved by copper azole. The performance of wood-based composites treated with copper azole, which was inferior to the biological resistance of treated C. japonica sapwood blocks, might depend on the thickness or layer profile, density as a result of porosity, uneven distribution of the preservative in the composites, and the susceptibility of the component raw materials.

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Penetration and distribution of paraffin wax in wood of loblolly pine and Scots pine studied by time domain NMR spectroscopy

Holzforschung ◽

10.1515/hf-2017-0030 ◽

2018 ◽

Vol 72 (2) ◽

pp. 125-131 ◽

Cited By ~ 10

Author(s):

Wang Wang ◽

Yiheng Huang ◽

Jinzhen Cao ◽

Yuan Zhu

Keyword(s):

Scots Pine ◽

Loblolly Pine ◽

Time Domain ◽

Treated Wood ◽

Weight Percent Gain ◽

Contact Angles ◽

Solid Content ◽

Paraffin Wax ◽

Distribution Data ◽

Water Contact

AbstractImpregnation of wood with paraffin wax emulsion (PWE) is a common eco-friendly approach for improving water repellency. In this study, loblolly pine (Pinus taeda) and Scots pine (Pinus sylvesteris) samples were impregnated with PWEs with different solid contents and particle sizes, and the influence of the impregnation parameters on wax penetration and distribution in treated wood was elucidated by time domain nuclear magnetic resonance (TD-NMR). A good linear correlation (R2=0.981) between wax content determined by TD-NMR and weight percent gain (WPG) of the impregnated wood was established. According to wax loading and distribution data, loblolly pine has a much better permeability than Scots pine. With decreasing solid content and particle size, the penetration of PWE increases in both species. The water contact angles (CA) on the surface at different depths of wood were also determined, and the CA results were consistent with the wax distribution found by the TD-NMR analysis.

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Preservative effect of Tetraclinis articulata and Cedrus atlantica wood extractives against fungal decay

Madera y Bosques ◽

10.21829/myb.2020.2632093 ◽

2020 ◽

Vol 26 (3) ◽

Author(s):

Noura Salhi ◽

Abdelwahed Fidah ◽

Mohamed Rahouti ◽

My Rchid Ismaili ◽

Bouselham Kabouchi ◽

...

Keyword(s):

Treated Wood ◽

Wood Decay ◽

Wood Preservative ◽

Fungal Decay ◽

Decay Fungi ◽

Plant Essential Oils ◽

Cedrus Atlantica ◽

Mass Losses ◽

Tetraclinis Articulata ◽

Wood Decay Fungi

Testing environmentaly-friendly plant essential oils for their ability to protect non-durable wood against wood decay fungi is a research topic of current interest. In this study, wood preservative potential of extracts from the wood of the durable species, Tetraclinis articulata and Cedrus atlantica were assessed on non-durable maritime pine sapwood, Pinus pinaster var atlantica, after exposure to three wood decay fungi, according to the EN 113 Standard. Significant differences were observed between treatment effects of these extracts, between fungal decay levels and between oils concentrations. Overall, mean mass losses of treated wood specimens were above 8%. T. articulata root burl extract gave the best protection level for this type of wood against Gleophyllum trabeum and Rhodonia placenta but only at test concentrations above 0.1%v/v. However, efficacy levels of both extracts’ treatments, applied at the tested concentrations, were judged insufficient on the basis of the NF EN 113 standard used.

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