• Journal of the Korean Society of Clothing and Textiles
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• v.30 no.11 s.158
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• pp.1581-1588
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• 2006

The effects of removal of lignin or hemicellulose on the cottonizing and pulping characteristics of kenaf fiber were studied by comparing the conditions of non-cellulosic material contents, fiber lengths and dyeability. And the effects of lignin or hemicellulose on dyeability of the kenaf fiber using CI Direct Green 26 and CI Direct Red 81 were investigated. The results were as follows. The lignin contents decreased and the kenaf fiber became shorter and finer as the reaction time with sodium chlorite increased. The hemicellulose could be removed by treating sodium hydroxide solution to the fiber from which the lignin partly removed. The 80% of hemicellulose could be removed by 5% of sodium hydroxide solution in 5 minutes. But if lignin were not removed at all, hemicellulose could not be removed. The fiber lengths proper for apparel were obtained after treating sodium chlorite for 10-20 minutes and those for pulping were obtained after treating sodium chlorite for 40 minutes. The kenaf fibers from which lignin and hemicellulose partly removed were dyed with CI Direct Green 26 and CI Direct Red 81. Their dyeability increased as the removal rates of lignin increased. The ${\Delta}E$ values of kenaf fiber dyed with CI Direct Green 26 were lower than CI Direct Red 81.

• Journal of the Korean Society of Clothing and Textiles
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• v.31 no.12
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• pp.1682-1688
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• 2007

The effects of cultivar and DAPs on the lignin content and dyeability of the kenaf fibers were investigated. Four kenaf fiber samples were prepared from two cultivars, Tainung 2 and Everglades 41, and their 60 and 120 DAPs(days after planting) for the experiments. The lignin contents of the kenaf fibers of Tainung 2(T2) and Everglades 41(E41) were $11.29{\sim}12.78%$. Both T2 and E41 kenaf fibers had comparable amount of lignin, and klason lignin of the fibers was $2.5{\sim}3$ times as much as much as acid-soluble lignin. In both T2 and E41, 120 DAPs kenaf have 1% more lignin than 60 DAPs kenaf. The moisture regains of the four kenaf fiber samples were almost the same as $10.25{\pm}0.05%$. The absorbances of residual solution after dyeing for $1{\sim}180$ minutes with Red 81 at maximum wavelength 520 nm and Green 26 at 600 nm were measured. Comparing to Green 26, the dyeing rate of Red 81 was rapid and equilibrium state was reached in 12 minutes. The CIE $L^*,\;a^*, \;b^*,\;{\Delta}E$ and K/S values of the kenaf fibers dyed with Red 81 and Green 26 were measured as well. The dye exhaustion ratio of 60 DAPs kenaf was higher than that of 120 DAP.