• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.9
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• pp.532-540
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• 2019

PET microfibers with various diameters (0.5, 0.2, 0.06, and 0.01 dpf) were dyed with a dispersed dye (C.I. Disperse Blue 56) at various temperatures. The dyeing process was conducted under infinite dyebath conditions at constant temperatures. The effects of the dyeing temperature and diameter on the partition coefficient, affinity, and diffusion coefficient of disperse dyes were studied. The curve of isotherms was fitted well to Nernst-type model in a large range of initial dye concentrations. At the same temperature, the partition coefficient and affinity decreased with increasing sample diameter due to the increase in surface area. At all deniers, the partition coefficient and affinity decreased with increasing temperature because the dyeing process is an exothermic reaction. In addition, the decrease in radius of the sample gives rise to a decrease in the heat of dyeing. The fine diameter of the sample resulted in an increased surface area but decreased space between the microfibers. Consequently, decreasing the diameter of the microfibers leads to a decrease in the diffusion coefficient. At the same diameter, the diffusion coefficient increased with increasing temperature because of rapid dye movement and the large free volume of the sample inside. In addition, thermal dependence of the diffusion coefficient increased when the diameter of the sample increased.

• Journal of the Korean Wood Science and Technology
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• v.35 no.3
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• pp.70-78
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• 2007

This study explored the efficient dyeing method of aged chestnut wood using the natural dyes extracted from Gardenia jasminoides for, grandiflora, Carthamus tinctorius L., Rhus javanica L., Lithospermum erythrorhizon S. et Z., Caesalpinia sappan L. and Castanea crenata S. et Z.. The color variation of the dyed chestnut woods was also quantitatively evaluated. The wood specimens revealed abundant colors through different dyeing conditions such as dyeing temperature, dye pH, soaking time, and brushing frequency. The chroma and stain concentration of colored woods were calculated with $L^*$, $a^*$ and $b^*$ in order to make color tone measurement. Brushing treatment for colored wood was confirmed as a more economical dyeing method than soaking treatment requiring more time when natural dyeing was done. Furthermore, the desirable tone and shade of color was easily obtained by repetitive brushing treatment using low color tone. During natural dyeing, good color expression was made with high temperature and acidic condition of a dyeing liquor.