Colour modification of poplar wood by steaming for brown colour

Banadics, Endre Antal; Tolvaj, László

doi:10.1007/s00107-019-01397-9

Cited by 17 publications

(8 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Information on changes in color of maple wood during thermal treatment in the form of decreasing values on the L* coordinate, increase in color saturation (chroma) C* and total color difference ∆E*, is given in Table 3. The decrease in values of the coordinate of lightness L* of thermal treated wood is in line with reports of wood darkening in technological processes such as wood steaming (Dianisková et al 2008;Tolvaj et al 2009Tolvaj et al , 2010Hadjiski and Deliiski 2016;Dzurenda 2013Dzurenda , 2018bBanadics and Tolvaj 2019), or high temperature wood drying in a superheated steam environment (Klement and Marko 2009;Baranski et al 2017;Klement at al. 2019).…”

Section: Resultssupporting

confidence: 85%

Evaluation of the process thermal treatment of maple wood saturated water steam in terms of change of pH and color of wood

Dzurenda

Geffert

Geffertova

et al. 2020

BioRes

View full text Add to dashboard Cite

Changes in maple wood’s pH and color (Acer pseudoplatanus) were evaluated before and after thermal treatment process with saturated water steam. Maple wood was thermally treated at temperatures: tI = 105 ± 2.5 °C, tII = 125 ± 2.5 °C, and tIII = 135 ± 2.5 °C for τ ≤ 12 hours. Direct pH measurement of maple wood with a moisture content above the fiber saturation point (FSP) was performed using a pH-meter SI 600 with a Lance FET + H puncture probe. The polynomial dependence of pH and total color difference ∆E* on temperature t time τ was calculated by statistical processing of measured results. The correlation between the total color difference ∆E* of maple wood in the process of thermal color modification and the pH value is expressed y the equation: ∆E* = 4.5516∙(pH)2 – 48.405∙(pH) + 134.35. This dependence is a suitable tool for assessing the achieved color change based on the change of wood pH in the technological process.

show abstract

Section: Resultssupporting

confidence: 85%

Evaluation of the process thermal treatment of maple wood saturated water steam in terms of change of pH and color of wood

Dzurenda

Geffert

Geffertova

et al. 2020

BioRes

View full text Add to dashboard Cite

show abstract

“…It can be attributed to the lignin condensation reaction with the by-products formed by the degradation of hemicellulose during the saturated steam heat treatment. Moreover, the degradation of cellulose and hemicellulose content is another reason for relative lignin content increment [ 26 , 27 , 28 , 29 , 30 ].…”

Section: Resultsmentioning

confidence: 99%

Change in Micro-Morphology and Micro-Mechanical Properties of Thermally Modified Moso Bamboo

et al. 2022

View full text Add to dashboard Cite

In recent years, saturated steam heat treatment has been considered as an environmentally friendly and cost-effective modification method compared with traditional heat treatment media. In this study, bamboo was treated by saturated steam, and the change in chemical composition, cellulose crystallinity index, micro-morphology, and micromechanical properties were analyzed by a wet chemistry method, Fourier transform infrared (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD), nanoindentation, and so on. Results illustrated that the parenchyma cell walls were distorted due to the decomposition of hemicellulose and cellulose in bamboo samples. As expected, the hemicellulose and cellulose content decreased, whereas the lignin content increased significantly. In addition, the cellulose crystallinity index and thus the micromechanical properties of bamboo cell walls increased. For example, the hardness increased from 0.69 GPa to 0.84 GPa owing to the enhanced crystallinity index and lignin content.

show abstract

“…In particular, the extractives may play a significant role in the formation of secondary colour compounds during hydrothermal treatment. According to previous studies, colour changes of wood can be due to the formation of new chromophore groups that arise from polysaccharide degradation, dehydration products, free radicals and the phenolic hydroxyl groups of lignin [23,25]. Based on a comparison of changes in the colour coordinates L*, a* and b* and selected chemical characteristics of birch wood (hemicelluloses and extractives), it can be concluded that mode II, which does not significantly decrease the hemicellulose content, seems to be the most advantageous.…”

Section: Resultsmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 98%

Impact of Steaming Mode on Chemical Characteristics and Colour of Birch Wood

Geffert

Geffertova

Výbohová

et al. 2020

Forests

View full text Add to dashboard Cite

The aim of this work was to evaluate the changes of the chemical components in birch wood (Betula pendula Roth) caused by steaming with saturated steam at three temperatures—105 °C, 125 °C and 135 °C. In the samples of the original wood and wood after steaming, select chemical characteristics were determined, and wood, isolated holocellulose and Seiferts’s cellulose were analysed by attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. The greatest changes in the birch wood characteristics were observed in steaming mode III (135 °C). The differential spectra of the birch wood samples indicated that the hemicelluloses were significantly degraded and that the dehydration reactions were able to proceed. A clear increase in both unconjugated and conjugated carbonyls was seen only in mode III. The findings also confirmed the greater sensitivity of the guaiacyl lignin contained in broadleaves to elevated steaming temperatures, as well as the course of the thermal oxidation reactions and the formation of new carboxyls in mode III. The decrease in the ratio of absorbances H 1732/2900 and H 1243/2900 demonstrated the cleavage of acyl (acetyl and formyl) groups from birch wood hemicelluloses. The qualitative and quantitative changes of the hemicelluloses and extractive substances in birch wood during steaming were well-correlated with the measured pH values and wood colour.

show abstract

Colour modification of poplar wood by steaming for brown colour

Cited by 17 publications

References 3 publications

Evaluation of the process thermal treatment of maple wood saturated water steam in terms of change of pH and color of wood

Evaluation of the process thermal treatment of maple wood saturated water steam in terms of change of pH and color of wood

Change in Micro-Morphology and Micro-Mechanical Properties of Thermally Modified Moso Bamboo

Impact of Steaming Mode on Chemical Characteristics and Colour of Birch Wood

Contact Info

Product

Resources

About