Homogenization of the Color of Beech Sapwood and False Heartwood by the Steaming Process
Abstract
:1. Introduction
2. Materials and Methods
3. Results and Discussion
- (a)
- By steaming beech wood with saturated moist air with a temperature of tI = 95 °C, the unification of the color of the sapwood with the false heartwood does not occur within τ = 24 h. The sapwood darkens and takes on a pale brown color. The heartwood has lightened to a darker shade of pale brown than the sapwood. However, the significant color contrast between the sapwood zone and the heartwood zone, which is ∆E1* = 14.8 for unsteamed wood and reduced to ∆E1* = 5.5 for steamed wood at the steaming temperature tI = 95 °C, is removed. The mentioned changes occur in beech wood by a decrease in the values on the lightness coordinate by ∆L* = −7.5 and an increase in the values of the red color coordinate by ∆a* = +3.1. For wood with a false heartwood, the values increase, both for the lightness coordinate by ∆L* = +2.7 and for the red color coordinate by ∆a* = +1.0.
- (b)
- Through the process of steaming beech wood with saturated water steam at a temperature of tII ≈ 105 °C, the unification of the colors of sapwood and false heartwood occurs after 18 h of the technological process. The average values of the unified color of steamed sapwood and false heartwood in the color space are CIE L*a*b*: L* = 61.3 ± 2.2, a* = 12.4 ± 1.3 and b* = 19.5 ± 1.4. The mentioned uniform coloring of the steamed wood is achieved by the significant darkening of the sapwood and slight darkening of the wood of the false heartwood. The degree of darkening of steamed beech wood is quantified by the decrease in the values on the lightness coordinate by ∆L* = −17.0 and the increase in the values on the red color coordinate by ∆a* = +3.3, the slight darkening of the steamed wood of the false heartwood quantifies the decrease in the value of the lightness coordinate by ∆L* = −2.6 and the increase in the value of the red color official by ∆a* = +0.8.
- (c)
- Unification of the colors of the sapwood with the wood of the false heartwood by the process of steaming with saturated water steam with temperatures tIII ≈ 120 °C to a dark brown–gray color occurs after 9 h of steaming. The average values of the dark brown–gray color of steamed beech wood in the color space are L* = 55.9 ± 1.9, a* = 12.3 ± 1.2, b* = 19.6 ± 1.3. The unification of the colors by the steaming process is achieved both by a decrease in the values of the coordinate of the lightness of the sapwood by ∆L* = −22.5 and of the false heartwood by ∆L* = −15.2, as well as by an increase in the values of the coordinate of the red color of the sapwood by ∆a* = +3.1 and wood with false heartwood by ∆a* = +0.9.
4. Conclusions
Author Contributions
Funding
Data Availability Statement
Conflicts of Interest
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Temperature of Saturated Water Steam | tmin [°C] | tmax [°C] | t4 [°C] | Wood Color Homogenization Time | |||||
---|---|---|---|---|---|---|---|---|---|
Mode I | 92 | 98 | 92 | τ1 = 4 h | τ2 = 8 h * | τ3 = 12 h * | τ4 = 16 h * | τ5 = 20 h * | τ6 = 24 h |
Mode II | 102 | 108 | 100 | ||||||
Mode III | 117 | 123 | 100 |
Beech Wood | Steaming Time [h] | Values in the Color Space CIE L*a*b* | The Difference between the Color of Sapwood and False Heartwood | Dispersion of Wood Color | |||
---|---|---|---|---|---|---|---|
L* | a* | b* | ∆E1* | ∆Esx* | |||
Unsteamed | Sapwood | 0 | 78.5 ± 2.5 | 9.2 ± 1.6 | 19.5 ± 1.8 | 14.8 | 3.5 |
False heartwood | 63.8 ± 3.6 | 11.5 ± 1.8 | 19.9 ± 1.6 | 4.3 | |||
Mode I tI = 95 ± 3 °C | Sapwood | 24 | 71.0 ± 2.1 | 12.1 ± 1.2 | 19.3 ± 1.5 | 5.5 | 2.8 |
False heartwood | 65.5 ± 2.8 | 12.5 ± 1.6 | 19.5 ± 1.4 | 3.5 | |||
Mode II tII = 105 ± 3 °C | Sapwood | 18 | 61.5 ± 1.9 | 12.5 ± 1.2 | 19.4 ± 1.4 | 0.4 | 2.6 |
False heartwood | 61.2 ± 2.3 | 12.3 ± 1.4 | 19.6 ± 1.4 | 3.0 | |||
Mode III tIII = 120 ± 3 °C | Sapwood | 9 | 56.0 ± 1.8 | 12.3 ± 1.1 | 19.5 ± 1.2 | 0.3 | 2.4 |
False heartwood | 55.8 ± 2.1 | 12.4 ± 1.3 | 19.7 ± 1.4 | 2.8 |
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Dzurenda, L.; Dudiak, M. Homogenization of the Color of Beech Sapwood and False Heartwood by the Steaming Process. Forests 2024, 15, 1009. https://doi.org/10.3390/f15061009
Dzurenda L, Dudiak M. Homogenization of the Color of Beech Sapwood and False Heartwood by the Steaming Process. Forests. 2024; 15(6):1009. https://doi.org/10.3390/f15061009
Chicago/Turabian StyleDzurenda, Ladislav, and Michal Dudiak. 2024. "Homogenization of the Color of Beech Sapwood and False Heartwood by the Steaming Process" Forests 15, no. 6: 1009. https://doi.org/10.3390/f15061009
APA StyleDzurenda, L., & Dudiak, M. (2024). Homogenization of the Color of Beech Sapwood and False Heartwood by the Steaming Process. Forests, 15(6), 1009. https://doi.org/10.3390/f15061009