Colour responses from wood, thermally modified in superheated steam and pressurized steam atmospheres

Dagbro, Ola; Torniainen, Petteri; Karlsson, Olov; Morén, Tom

doi:10.1080/17480272.2010.520739

Cited by 24 publications

(24 citation statements)

References 11 publications

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“…To eliminate or decrease these disadvantages of wood, various techniques have been used for bulk or surface treatments, such as heat treatment (Cademartori et al 2013), hydrothermal treatment (Dagbro et al 2010;Grinins et al 2013), oil heat treatment (Palanti and Susco 2004;Palanti et al 2011), hot pressing treatment (Candan et al 2013) and also in situ polymerisation (Li et al 2013;Islam et al 2014), which has been used to improve the hydrophobicity and dimensional stability of wood. Moreover, extensive chemical modification techniques have been used to enhance the photostabilisation of wood, as well as dimensional stability and hydrophobicity (Prakash and Mahadevan 2008;Farahani and Taghizadeh 2010;Jebrane et al 2011;Xiao et al 2012;Thybring 2013).…”

Section: Introductionmentioning

confidence: 99%

Chemical modification of fast-growing eucalyptus wood

et al. 2014

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In this study, a new simple method for chemical modification of wood from fast-growing Eucalyptus saligna (blue gum) was tested by a two-step treatment with methacryloyl chloride. The wood samples were submerged in a solution of 10 % methacryloyl chloride in dichloromethane for 15 h and then exposed to three temperatures: air dried, 50 and 100°C for 2 h. The chemical modifications of the wood were examined by ATR-IR and 13 C CP/MAS solid-state NMR; quantitative chemical composition of wood samples by means of wet chemical quantification, HPLC, TGA; colorimetric evaluation by CIELAB method and UV-Vis spectroscopy. Water uptake tests were also performed. A partial substitution of the hydroxyl by methacrylate groups on the cell wall of blue gum wood was observed, and also loss of a hemicelluloses fraction after the treatments. The colour change increased with increasing temperature in the second step of the treatment. Dimensional stability and water repellence were improved by 40-50 and 60-75 %, respectively.

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Section: Introductionmentioning

confidence: 99%

Chemical modification of fast-growing eucalyptus wood

et al. 2014

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“…The thermal modification process can be controlled by either the temperature of the wood or the chamber environment (Dagbro et al 2010). In the case of this study, the treatment schedules were "time-based" and the air temperature was measured at several points inside the chamber.…”

Section: Methodsmentioning

confidence: 99%

Industrial Validation of the Relationship between Color Parameters in Thermally Modified Spruce and Pine

Torniainen¹,

Elustondo²,

Dagbro³

2015

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Thermal modification causes the darkening of wood throughout its crosssection because of chemical changes in the wood. After treatment, naturally light wood species look darker or even tropical, depending predominantly on the treatment temperature and processing time. This study investigates the suitability of using color measurement to determine treatment intensity at the industrial scale. The color was determined using the L*, a*, and b* color space, also referred to as CIELab, and the relationship between lightness (L*) and the color parameters (a*) and (b*) was investigated for thermal modification treatments at 190 and 212 °C. The wood species studied were pine (Pinus sylvestris L.) and spruce (Picea abies L.). The results showed that yellowness (+b*) and redness (+a*) had a significant prediction ability for class treatments at 190 and 212 °C, respectively. After treatment, there were no noticeable differences in color between the species, but sapwood was darker than heartwood in both untreated and thermally modified wood. The thickness of the boards had a proportionally darkening effect on the color values.

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“…Esteves et al [6] erreichten bei einer vergleichbaren Behandlung jedoch mit 190 °C bei 12 h Behandlungszeit für Kiefer eine relative Farbveränderungen in der tangentialen Ebene von ∆L = 34,8 %, ∆a = 78,6 % und ∆b = 5,7 %, wobei gesagt werden muss, dass die Resultate in der genannten Studie stark streuen, was sich speziell auf die anatomischen Schnittrichtungen bezieht und somit auch die Vergleichbarkeit limitiert. Bei einer Untersuchung von Dagbro et al [5], bei welcher auch mit überhitztem Dampf und Dampf unter Druck gearbeitet wurde, ergeben sich im …”

Section: Introductionunclassified