Dzurenda, Ladislav, 1955- Mode for hot air drying of steamed beech blanks while keeping the colours acquired in the steaming process / Ladislav Dzurenda. -- Graf., tab. -- Lit. - The analysis of the impact of proposed external conditions for hot air drying of steamed beech wood (Fagus sylvatica L.) blanks from the initial moisture content of w1 ≈ 50 % to final moisture content w2 = 10 % on the maintaining the colour of wood obtained in the process of steaming at the following modes: mode I (tI = 95 ± 2.5 °C), mode II (tII = 115 ± 2.5 °C), mode III (tIII = 135 ± 2.5 °C) is presented in the paper. The drying process is divided into two parts. Evaporation of free water from wet wood at drying medium temperatures ts = 35 ÷ 40 °C and relative humidity φ = 70 – 60 %, when there are no chemical changes in the lignin-saccharide complex of beech wood manifested by the decomposition of chromophore structures and the formation of new functional groups manifested by a change in the colour of the wood. Evaporation of bound water from beech wood below the hygroscopicity limit is performed at the temperatures ts = 70 ÷ 80 °C. The colour coordinates in the colour space CIE L*a*b* of beech wood steamed by mode I after drying are: L* = 69.6 ± 1.7; a* = 11.3 ± 0.9; b* = 19.6 ± 1.2, steamed by mode II are: L* = 64.6 ± 1.6; a* = 13.0 ± 0.7; b* = 22.7 ± 1.0 and steamed mode III are: L* = 54.5 ± 1.5; a* = 13.4 ± 1.1; b* = 25.3 ± 1.3. Differences in the colour of dried steamed beech wood according to the proposed drying mode and dried in an air-conditioned space is in the range of values ∆E* = 1.3 – 1.8.

In Acta Facultatis Xylologiae Zvolen : vedecký časopis Drevárskej fakulty. -- Zvolen : Technická univerzita vo Zvolene, 2022. -- ISSN 1336-3824. -- Vol. 64, no. 1 (2022), s. 81-88

I. Acta Facultatis Xylologiae Zvolen : vedecký časopis Drevárskej fakulty. -- Vol. 64, no. 1 (2022), s. 81-88

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