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

Holzforschung ◽  
2010 ◽  
Vol 64 (3) ◽  
Author(s):  
Cihat Tascioglu ◽  
Kunio Tsunoda

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.

Holzforschung ◽  
2006 ◽  
Vol 60 (1) ◽  
pp. 104-109 ◽  
Author(s):  
Takeshi Furuno ◽  
Fuyuki Wada ◽  
Sulaeman Yusuf

Abstract Insoluble metaborates were formed by impregnating wood with borax and metallic salts, and the biological resistance of samples treated with metaborates was evaluated. The double-diffusion process was carried out to form metaborate precipitates in sapwood specimens of Japanese cedar (Cryptomeria japonica). Water-saturated wood specimens were first impregnated by a saturated borax solution and then diffusion-penetrated with solutions of zinc sulfate or copper sulfate of different concentrations. In laboratory-scale termite tests of wood specimens treated with zinc and copper metaborates at five concentrations from 3% to 20% using a virulent subterranean termite (Coptotermes formosanus), metaborate-treated wood showed negligible weight loss, with high termite mortality at the lowest concentration of 3%. An additional termite test for treatments at lower concentrations of 1% and 2% revealed good termite resistance even with small weight gains of 2.3–6.7%. In field termite tests using a tropical dominant termite (Macrotermes gilvus) in Serpong, Indonesia, wood specimens of 2 cm (r)×2 cm (t)×10 cm (l) treated with metaborates at 5% and 20% showed little weight loss against termite attack for 2 months or more. In addition, in a decay test using a white-rot fungus (Trametes versicolor) and a brown-rot fungus (Fomitopsis palustris), metaborate-treated woods showed enhanced decay resistance. This superb enhancement of biological resistance against termite and decay attacks is considered to be attributable to the presence of metaborates containing effective components such as boron, zinc or copper in the cell walls, which were detected by EPMA observations.


Holzforschung ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Lukas Emmerich ◽  
Maja Bleckmann ◽  
Sarah Strohbusch ◽  
Christian Brischke ◽  
Susanne Bollmus ◽  
...  

Abstract Chemical wood modification has been used to modify wood and improve its decay resistance. However, the mode of protective action is still not fully understood. Occasionally, outdoor products made from chemically modified timber (CMT) show internal decay while their outer shell remains intact. Hence, it was hypothesized that wood decay fungi may grow through CMT without losing their capability to degrade non-modified wood. This study aimed at developing a laboratory test set-up to investigate (1) whether decay fungi grow through CMT and (2) retain their ability to degrade non-modified wood. Acetylated and 1,3-dimethylol-4,5-dihydroxyethyleneurea (DMDHEU) treated wood were used in decay tests with modified ‘mantle specimens’ and untreated ‘core dowels’. It became evident that white rot (Trametes versicolor), brown rot (Coniophora puteana) and soft rot fungi can grow through CMT without losing their ability to degrade untreated wood. Consequently, full volume impregnation of wood with the modifying agent is required to achieve complete protection of wooden products. In decay tests with DMDHEU treated specimens, significant amounts of apparently non-fixated DMDHEU were translocated from modified mantle specimens to untreated wood cores. A diffusion-driven transport of nitrogen and DMDHEU seemed to be responsible for mass translocation during decay testing.


Holzforschung ◽  
2018 ◽  
Vol 72 (12) ◽  
pp. 1079-1086 ◽  
Author(s):  
Jed Cappellazzi ◽  
Karl Maguire ◽  
Rob Nelson ◽  
Jeffrey J. Morrell

AbstractAir-seasoning is a simple method for moisture management in utility poles prior to treatment, but it involves the risk of fungal invasion during drying. These fungi can be eliminated by heat treatment, but fungi surviving in the installed poles are a quality problem. In this context, the incidence of decay fungi was investigated in 963 creosote-treated Scots pine (Pinus sylvestris) poles of varying ages in a utility system in Ireland. Thirty-seven percent of increment cores removed from the poles contained at least one viable basidiomycete. There was no relationship between pole age or distance above the groundline and fungal isolations.Phlebiopsis gigantea, a white rot fungus, was the most common isolate followed byNeolentinus lepideusandSistotrema brinkmannii. The results highlight the importance of including a sterilizing process during treatment and maintaining quality controls when purchasing large numbers of poles.


BioResources ◽  
2011 ◽  
Vol 6 (3) ◽  
pp. 2719-2731 ◽  
Author(s):  
Yi P. Teoh ◽  
Mashitah M. Don ◽  
Salmiah Ujang

Wood-decaying fungi present a serious threat to items made from rubberwood (Hevea brasiliensis). Though conventional chemical control has been a successful method for preserving wood against stain and decay fungi growth, the effects of these chemicals are of concern because they create problems for the environment and public health. Pycnoporus sanguineus (P. sanguineus), is a white-rot fungus that invades wood during its growth, storage, or use, causing decay or other property changes. It was considered in this work as a potential source of bioactive compounds and investigated for its natural antifungal activity using a minimum inhibitory concentration assay against wood-degrading fungi. It was found that media consisting of 10.0 g/L malt extract, yeast extract, dextrose, and maltose, respectively at pH 4.7±0.2 provided the highest biomass production by P. sanguineus. Results showed that the antifungal properties of methanol and water extract of P. sanguineus mycelia and supernatant ranged from MIC values of 0.1 to 5.0 µg/µL. 4H-Pyran-4-one,2,3-dihydro-3,5-dihydroxy-6-methyl- (DDMP) was found to be the major component in the extract of this fungus, based on analysis using gas chromatography – mass spectrometry.


Forests ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 41 ◽  
Author(s):  
Darrel Nicholas ◽  
Amy Rowlen ◽  
David Milsted

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.


Holzforschung ◽  
2006 ◽  
Vol 60 (4) ◽  
pp. 455-458 ◽  
Author(s):  
S. Nami Kartal

Abstract The decay and termite resistance of boric acid (BA)- and di-sodium octoborate tetrahydrate (DOT)-treated sugi sapwood was tested in the context of additional heat treatments at two temperature levels. Heat treatments had no effect on boron release and almost all boron was leached from specimens during a 10-day weathering period. Decay tests with the brown-rot fungus Fomitopsis palustris and the white-rot fungus Trametes versicolor and a 3-week termite resistance test with the subterranean termite Coptotermes formosanus were performed. Heat treatments did not increase the decay resistance of either BA- or DOT-treated specimens against the brown-rot fungus. However, the decay resistance of BA-treated specimens against the same fungus increased after heat treatment at 220°C for 2 h. Heat treatments at 180°C for 4 h and 220°C for 2 h also resulted in increased decay resistance of DOT-treated specimens against T. versi-color. Increased resistance against termite attack was observed only in DOT-treated specimens heated at 180°C for 4 h or at 220°C for 2 h. Accordingly, a synergistic effect between heat and DOT treatments was observed for resistance against white-rot decay and termites.


2020 ◽  
Vol 19 (2) ◽  
pp. 112-116
Author(s):  
Luana Maria dos Santos ◽  
Erick Martins Nieri ◽  
Flávia Alves Pereira ◽  
Sandra Mara Krefta ◽  
Jéssica Batista da Mata

The companies in the forestry sector seek highly durable wood, prioritizing the use of planted forests, and the thermal treatment is a viable alternative to provide quality to these woods. Thus, the objective of the study was to evaluate the resistance of the heat-treated Pinus taeda L wood by the attack of white rot fungus Trametes versicolor (L.) CG Lloyd. The P. taeda L. wood was deployed in joinery to obtain samples with dimensions of 30 x 15 x 2.5 cm (length x width x thickness), being treated at temperatures of 140, 160 and 180ºC. From these, 1.0 x 1.0 x 1.0 cm specimens were obtained and subjected to the fungus for six weeks. The accelerated rot test was carried out in accordance with the ASTM D2017 standard. The experiment was conducted in a completely randomized design with four treatments (T1 = 0; T2 = 140°C; T3 = 160°C and T4 = 180°C) and nine replications. The loss of mass caused by the fungus was less in heat treated wood. On the other hand, the increase in temperature did not provide greater resistance to the material. In conclusion, heat treatment has reduced the degradation caused by the white rot fungus Trametes versicolor. Heat treatment at 140°C is indicated to avoid loss of mass in P. taeda L. woods submitted to the fungus T. versicolor. All treated woods were classified as highly resistant.


Botany ◽  
2009 ◽  
Vol 87 (1) ◽  
pp. 26-35 ◽  
Author(s):  
Giuliana Deflorio ◽  
Erwin Franz ◽  
Siegfried Fink ◽  
Francis Willis Mathew Robert Schwarze

Host responses, i.e., formation of reaction and barrier zones, were studied in the xylem of Douglas-fir, beech, oak, and sycamore trees, after wounding and artificial inoculation with brown-, soft-, and white-rot fungi. The objective of this study was to determine whether strongly invasive wood-decay fungi trigger a higher magnitude of host response than weakly invasive fungi. Differences in active host response, observed microscopically, depended on wood anatomy. Restriction of discoloration and decay by reaction zones was primarily influenced by the content and distribution of parenchyma cells within the sapwood of each host. By contrast, barrier-zone anatomy showed similarities to the basic xylem structure of each host, except for some cell types that were either reduced in number or absent. Regardless of the decay fungus inoculated, individual trees of each host responded differently. With the exception of beech trees inoculated with the soft-rot fungus Kretzschmaria deusta (Hoffm.: Fr.) P. Martin and the white-rot fungus Trametes versicolor (L.: Fries) Pilát, host response appeared to be nonspecific, as the degree of fungal invasiveness did not influence the magnitude of host response within the xylem of investigated trees.


2020 ◽  
Vol 12 (11) ◽  
pp. 4431
Author(s):  
Rasdianah Dahali ◽  
Seng Hua Lee ◽  
Zaidon Ashaari ◽  
Edi Suhaimi Bakar ◽  
Hidayah Ariffin ◽  
...  

In this study, the effect of superheated steam (SHS) treatment on the changes of the chemical composition and biological properties of two tropical hardwoods was investigated. SHS was carried out on light red meranti (Shorea spp.) and kedondong (Canarium spp.) wood with dimensions of 410 × 25 × 25 mm, using superheated steam as the heating medium. Wood samples were heat-treated at nine treatment levels, ranging from 172 to 228 °C and 95 to 265 min, respectively. The chemical constituents and resistance against white rot fungus (Pycnoporus sanguineus) and subterranean termite (Coptotermus curvignathus) of the treated wood were evaluated. A significant reduction in holocellulose content and increment in lignin was observed after SHS treatment. Consequently, the resistance against white rot fungus and termites improved. The biological durability improved with an increasing treatment temperature and time. A regression analysis revealed that the reduced equilibrium moisture content imparted superior biological resistance to the treated wood. Weight loss caused by the thermal degradation also served as a good indicator for fungal decay, as the loss of weight was directly proportional to the improvement in fungal resistance. However, this did not apply to termite resistance, as a very weak relationship was found between the two variables.


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