• Textile Coloration and Finishing
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• v.18 no.5 s.90
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• pp.1-7
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• 2006

The dyeing properties of the several reactive dyes possessing different types of the reactive group on nylon 6 fabric have been investigated. Dyeing of nylon fiber with commercial reactive dyes was dependent on the dye bath pH. As pH increased, the extent of exhaustion decreased due to the deprotonation of the amino end group. But, the extent of fixation increased because of the enhanced reactivity with nylon fiber. It was found that all reactive dyes could be applied to nylon 6 reasonably at pH 5-6. But, the conflicting requirements of dye exhaustion and covalent bond formation limited the extent of fixation efficiency. The best method to improve the extent of the fixation efficiency of the reactive dyes was the conversion of sulphatoethylsulphone group to vinylsulphone group before dyeing with trisodium phosphate. The converted Supra type reactive dye gave the highest extent of fixation efficiency, which was about 90%.

• Textile Coloration and Finishing
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• v.14 no.3
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• pp.26-33
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• 2002

Dyeing properties and crosslinking effect of bifunctional reactive dyes on chitosan fiber were investigated to improve the stability of chitosan fiber against the mild acidic solution and the wet processing. Chitosan fibers were crosslinked with epichlorohydrin for comparing purpose, and dyed with C. I. Reactive Red 194, C. I. Reactive Blue 50, and the reactive dye having two $\alpha$-bromoacrylamide groups at various concentrations. The initial dyeing rates of reactive dyes are rapid and chitosan fibers absorb the relatively large amount of dyes. The chitosan fibers dyed with these dyes show the low degree of swelling and the low solubility in 1 % acetic acid solution and also represent the higher thermal stability The reactive dye with two $\alpha$-bromoacrylamide groups shows higher crosslinking effect than other dyes.

• Textile Coloration and Finishing
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• v.11 no.2
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• pp.46-54
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• 1999

The conventional dyeing of wool/cotton blends involves a two bath two step method, i.e., after dyeing of the wool component with acid dyes in an acidic dyebath at $100^\circ{C}$, the dyeing of the cotton component with reactive dyes in an alkaline dyebath is performed. In order to overcome the disadvantage of the conventional two bath two step dyeing method of wool/cotton blends, it had prompted significant effort to the development of the one bath dyeing method which can accomplish savings in time, energy and water usage. To improve dyeing property of wool/cotton blends, cotton component was pretreated with cationizing agent containing chlorohydrine group in aqueous solution of sodium hydroxide. This study was carried out to investigate dyeing possibilities of wool/cationized cotton blends with acid dye/reactive dye by one bath two step method.

• Textile Coloration and Finishing
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• v.25 no.4
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• pp.262-270
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• 2013

Temporarily solubilized reactive disperse dyes containing ${\beta}$-sulfatoethylsulfonyl group were applied to 100% meta-aramid knitted fabric and their dyeing properties were investigated. Reactive disperse dyes showed relatively high K/S values on meta-aramid fabric when compared with conventional disperse dye or reactive dye, which showed very low K/S values. Color yields of reactive disperse dyes were highly dependent on dyeing pH and optimum results were obtained at pH 6. Percent exhaustion of reactive disperse dye on meta-aramid fabric was over 80% at 2% o.w.f of dye concentration. Wash fastness of pyridone-based reactive disperse dyes was very good to excellent while that of aminoazobenzene reactive disperse dyes was medium to good. Light fastness of all the reactive disperse dyes was very poor which seems to be due to the low photostability of meta-aramid fiber itself.

• Fibers and Polymers
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• v.6 no.3
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• pp.224-228
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• 2005

This paper focuses on the application of a novel mathematical limit approach derived for K/S values in reactive dyeing of cotton fabrics. The relation obtained from Kubelka-Munk equation is used because the Kubelka-Munk equation is the basic relationship among fabric reflectance, fabric dye content and dyestuff characteristics. The limit approach derived in a former paper is applied to the laboratory dyeings and the dyeing behavior of some reactive dyes on cotton knitted fabric has been obtained. The results of the laboratory experiments are discussed using the new mathematical approach. When the actual K/S values obtained from the dyeings and the calculated K/S values derived by the limit approach are considered independently, it is observed that the limit relation is val id for low dye concentration applications. When the K/S values are calculated taking the K/S value of the initial dyeing concentration $(0.1\;\%\;owf)$ as the starting concentration by applying the result of the derived limit approach, the calculated K/S values fit with the ones obtained in actual dyeings. It is concluded that the novel approach presented in the paper can be used in calculating the K/S values when the initial dyeings at low dye concentrations are carefully carried out.

• Textile Coloration and Finishing
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• v.21 no.5
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• pp.10-15
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• 2009

A mixed bi-functional reactive dye has been applied to the cotton and the cotton/hemp blend and their dyeing and fastness properties were compared. The cotton/hemp blend exhibited higher exhaustion values and better build-up property than cotton, presumably due to the lower crystallinity. Hence, the reproducibility of dyeing of hemp is expected to be excellent. Fastness properties of reactive dyes on cotton and cotton/hemp blend are found to be almost identical. The results obtained suggest that hemp in cellulosic fabric could be used as an important alternative to universal cotton in cellulose fabrics.

• Textile Coloration and Finishing
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• v.13 no.1
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• pp.55-60
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• 2001

Cotton fabric was deed with a reactive dye in water/dichloromethane two-phase immiscible solvent media. In order to minimize dye loss due to its hydrolysis, the reactive dyeing was carried out in dichloromethane containing a small amount of water. With only 2ml of water in 23m1 of dichloromethane, 1.0g of cotton fabric could be dyed perfectly. The uptake ratio was increased greatly, compared with that of normal reactive dyeing in a waters medium. It would seem that the one of hydrophobic solvents, dichloromethane, can assist the eden dyeing as it disperses a small amount of dye-dissolved water phase and conveys this water phase to the fabric entirely and uniformly.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2009.03a
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• pp.175-176
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• 2009

Energy saving and environment-friendly dyeing method of cotton with reactive dyes is the ultra low liquor ratio dyeing because it reduces the total quantity of water, dye, salt and alkali during the dyeing process in the effluent as well as the energy consumption. However, this method may not guarantee the quality of the dyeing results due to the specs or unlevel dyeing depending upon the dyes used. The study has focused on the effect of leveling agents in the dyeing of cotton with reactive dyes under the ultra low liquor ratio (1:5). Especially Sunfix N/B MF-D which was selected for ULLR showed low-leveled dyeing comparing with the other MF-D series. A leveling agent having polycarbonate structure increased LDF values of Sunfix N/B MF-D without changing of dyeing fastness. We recommend some leveling agents to improve the leveling behavior for ULLR dyeing.

• Textile Coloration and Finishing
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• v.10 no.3
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• pp.1-9
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• 1998

The dyeing properties of modified wool were examined with a series of acid, reactive and cationic dyes. Cationic agent and sulphamic acid were applied to wool fabric for dye assist and resist effect. Wool pretreated with cationic agent showed better uptake of acid and reactive dyes than did untreated wool. On the other hand, the dyeing behavior of wool pretreated with sulphamic acid was found as follows : Acid dyes were poorly resisted with a hydrophobic mechanism but acid dyes were strongly resisted with a hydrophilic mechanism. Reactive dyes were also found to be effectively resisted. Sulphamic acid introduces sulphonate group into wool's structure, it has increased better uptake of cationic dyes than untreated wool. The degree of differential uptake depends on the level of pretreatment and produces a variety of tone-on-tone and multicolor effect in piece dyeing.

• Textile Coloration and Finishing
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• v.12 no.6
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• pp.372-379
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• 2000

Four kinds of neutral salts with different cations, LiCl, NaCl, KCl, and CsCl, were added to the dye bath to accurately understand the effect of cations on the reactive dyeing of silk with C. I. Reactive Black 5. The cations of salts added lowered the negative surface potential of the silk, improving equilibrium adsorption and the accessibility of the dyestuff to the fiber greatly and speeding up the dyeing rate in the order of $Li^+>Na^+>K^+>Cs^+$. The activation energy$(E_a)$ for the dyeing was in the order of$Li^+>Na^+>K^+>Cs^+$ but the activation free energy$(\Delta{G}^*)$, or the real energy barrier for the reaction, was in the order of $Li^+>Na^+>K^+>Cs^+$ because the degree of the contribution of E$^{a}$ to the activation entropy$(\Delta{S}^*)$ was $Li^+>Na^+>K^+>Cs^+$. It was found from this result that LiCl had the strongest lowering effect on the negative surface potential of silk. The decrease in $\Delta{S}^*$ should be attributed to the loosely bonded activated complex of dyestufffs, cations and fiber molecules at transition state. It was clarified from the Bronsted equation that salts had the ionic strength effect and the specific salt effect on the reactive dyeing.