Ten Essential Oils for Beech Wood Protection - Efficacy Against Wood-destroying Fungi and Moulds, and Effect on Wood Discoloration
This work analyses the anti-fungal efficacy and stability of 10 essential oils, as well as their colour stability, in wood. The efficacy of oils against the decay fungi Coniophora puteana and Trametes versicolor as well as the moulds Aspergillus niger and Penicillium brevicompactum was evaluated first on filter papers treated with 1, 3.5, 10%, or 100% concentrate, and then on beech wood treated with 10% solutions. Accelerated ageing of treated beech samples was done before mycological tests and consisted of heating, leaching followed by heating, and Xenotest followed by heating. The highest growth inhibition of moulds and C. puteana was caused by thyme, oregano, sweet flag, and clove oils, while the savory and birch oils were less effective. These oils are potentially useful for wood protection against brown-rot fungi and moulds, mostly in interior conditions. The essential oils had only a negligible effect against the white-rot fungus T. versicolor, which was more apparent after previous ageing of wood. Some essential oils with a yellow tone (birch, oregano, sweet flag, savory, and tea tree oils) significantly changed (p<0.05) the natural colour of beech wood, but the new colours were relatively stable and underwent only mild changes after accelerated ageing in Xenotest.
Plant essential oils for environment-friendly protection of wood objects against fungi
The study was aimed at testing environmental-friendly plant essential oils for their protecting efficiency of valuable woods against colonization by mould and wood-decay fungi. Sixteen essential oils were applied to Fagus orientalis and Pinus taeda wood samples by vacuum impregnation and infected with Aspergillus niger, Penicillium commune (moulds), Coniophora puteana (brown rot), Trametes versicolor (white rot), Chaetomium globosum (soft rot) and natural infection by airborne spores. Lavender oil, lemon grass oil and thyme oil were the most effective oils against all fungi tested.
Combinations of wood and silicate Part 6. Biological resistances of wood-mineral composites using water glass-boron compound system
SummaryWood-mineral composites were made by introducing inorganic substances into wood using the water glass (sodium silicate)-boron compound system (double treatment). Composites were also prepared with boron compounds alone (single treatment), and biological resistances of the two types of composites were evaluated and compared.After the leaching procedure, the composites using the water glass-boron compound system showed generally excellent termite resistances with the negligible weight losses of specimens and high mortalities of workers and soldiers. On the contrary, the single treatment and the double treatment using the reactants of non-boron compounds showed slight or little resistances against termite attacks, accounting for the high leachability of the inorganic substances formed in wood and/or low effectiveness of the chemicals.Also, the water glass-boron compound system was found to enhance greatly the decay resistances if water-soluble inorganic substances were fully removed out from the specimens. The formation of insoluble inorganic substances in the water glass-boron compound system proved to contribute much to the enhancement of biological resistances.