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Domingos I., Ferreira J., Cruz-Lopes L., Esteves B.

Drewno : prace naukowe, doniesienia, komunikaty

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2018

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vol. 61, nr 202

69--80

EN

A study was made of water-related properties of Pinus pinaster wood impregnated with paraffin or modified by heat treatment or furfurylation. Treated woods were submerged in water for periods ranging from 2 to 1680 hours. Water absorption, swelling, and dimensional stability in the radial and tangential directions – expressed as Anti-Shrinking Efficiency (ASE) – were determined. Water absorption increased with time, reaching approximately 140% after 1680 h for untreated and heat-treated wood, and 60% for paraffinated and furfurylated wood. The rate of swelling differed between the first hours of soaking and after prolonged immersion. The final swelling was approximately 9% and 6% for untreated pine, 8% and 4% for paraffinated pine, 5.5% and 3% for heat-treated pine and 2.5% and 1% for furfurylated pine (in the tangential and radial directions respectively). At the end of the soaking test, furfurylated pine had the best ASE of approximately 80% and 70% in the tangential and radial directions respectively, followed by heat-treated pine with 44% and 34%, and paraffinated wood with 35% and 13%.

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The effects of heat treatment on colour and glossiness of some commercial woods in Turkey

Gurleyen L., Esteves B., Ayata U., Gurleyen T., Cinar H.

Drewno : prace naukowe, doniesienia, komunikaty

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2018

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vol. 61, nr 201

81--90

EN

In this study, hornbeam (Carpinus betulus L.), poplar (Populus deltoides), chestnut (Castanea sativa Mill.) and Uludağ fir (Abies bornmülleriana Mattf.) were heat treated at 212°C for 1 hour and 2 hours by the ThermoWood® method. Colour and glossiness were determined and compared with untreated samples. Results showed that lightness (L*) decreased for all tested samples and that the decrease was higher with more intense treatments. Colour parameter a* (red/green) initially increased with heat treatment, then decreasing afterwards. The colour parameter b* (yellow/blue) on the other hand, decreased for Hornbeam and Chestnut and increased for Poplar and Uludag fir. Generally, the glossiness decreased with heat treatment for both measurements, along and across the grain. All factors and interactions were found to be significant (according to α = 0.05) with the exception of interaction (AB) for parallel (//) glossiness in 60°. The highest total colour change was achieved for Hornbeam (ΔE* = 41.58).

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Effect of heat treatment on the surface of selected exotic wood species

Ayata U., Gurleyen L., Esteves B.

Drewno : prace naukowe, doniesienia, komunikaty

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2017

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vol. 60, nr 199

105--116

EN

This study measured the effect of heat treatment according to the ThermoWood method on the colour and glossiness properties of selected exotic wood species. For this purpose, Afrormosia (Pericopsis elata), Doussie (Afzelia bipindensis), Frake (Terminalia superba) and Iroko (Chlorophora excelsa) were heat treated at 212°C for 1 hour and 2 hours using the ThermoWood method in Novawood Factory, Gerede, in Bolu, Turkey. After this process, the glossiness and colour of the untreated wood were tested in comparison with the heat-treated samples. The results show that the colour (L*, a* and b*) and glossiness (parallel and perpendicular to the grain at 20°, 60° and 85° angles) were changed by the treatment. Generally the L* and glossiness of the surface decreased and the ΔE* and a* increased with the intensity of the treatment.