Union dyeing of the photografted PET/wool blend fabrics with dimethylaminopropyl methacrylamide

Dimethylaminopropyl methacrylamide (DMAPMA) was grafted onto PET/wool blend fabrics by continuous UV irradiation. Union dyeing of the photografted fabrics was investigated using three reactive dyes of α-bromoacrylamide reactive groups. The influence of grafting yield, DMAPMA concentration, NaCl amount, pH value, and dyeing temperature on the dyeability was evaluated. The dyeability of both PET and wool components was improved significantly by the DMAPMA photografting and successive reactive dyeing. Although the dyeability of the PET component in the blend substantially was improved with higher grafting, equal dyeability between PET and wool was difficult to achieve due to more facile grafting and higher reactivity of the wool component compared with the modified PET component. However, the color fastness of the PET/wool blend fabric was excellent for all three colors. This study may offer a way to achieve union dyeing of PET/wool blend fabrics.     

Dyeing properties of nylon,PET, and N/P mixture fabric with reactive-disperse dyes having a sulfatoethylsulfone group

The dyeing and color fastness properties of two reactive-disperse dyes containing a sulfatoethylsulfone group on nylon, PET and N/P mixture fabrics were examined. The rate of dyeing on nylon fabric was greatly dependent upon dye bath pH. The final dye uptakes at all pH, however, were as high as 97 %. Color strength of the dyed nylon fabric linearly increased up to 0.5 %owf and then slowed down over 1 %owf dyeing. Washing and rubbing fastness of the dyed nylon fabric were excellent, but grade of light fastness was moderate. Dyeability of the reactive-disperse dyes on PET fabric was not much affected by pH, and K/S values of PET fabric dyed at pH 5–8 were lower than those of nylon fabric at all pH examined. Buildup and color fastnesses properties on PET fabric showed the same tendency with nylon fabric. The rate of dyeing of the reactive-disperse dyes on nylon fabric was faster than on PET fabric when both fabrics were dyed simultaneously in the same dye pot, resulting in higher color strength of nylon than PET. The reactive-disperse dyes were found to be adequate to the one-bath, one-step dyeing of N/P mixture fabric when applied at pH 5 and 120 °C.     

Preparing fluorescent wool/acrylic blends with a hemicyanine reactive cationic dye

Wool/acrylic blends were dyed with a hemicyanine reactive cationic dye, Dye 1, to prepare the fluorescent wool/acrylic blends in this article. The study initially focuses on the optical properties of Dye 1, followed by dyeing properties of Dye 1, then ended with fluorescent properties of the dyed wool/acrylic blends. The results show that the exhaustion, fixation, and fastness to washing and rubbing of Dye 1 on wool, acrylic, and wool/acrylic blend were good throughout. The dyed wool/acrylic blends can emit obvious fluorescence. In addition, according to the EN-1150 standard (1999), the chromaticity of dyed wool/acrylic blends meet the requirements of fluorescent pink when the dye concentrations are suitable.     

Dyeing and fastness properties of a reactive disperse dye on PET, nylon, silk and N/P fabrics

Dyeing and color fastness properties of a reactive disperse dye containing an acetoxyethylsulphone group on PET, Nylon, silk and N/P fabrics were examined. The reactive disperse dye exhibited almost the same dyeing properties on PET fabric as a conventional disperse dye except the level of dye uptake. The most appropriate pH and dyeing temperature for the dyeing of Nylon fabric were 7 and 100°C respectively. The build-up on Nylon fabric was good and various color fastnesses were good to excellent due to the formation of the covalent bond. Application of the reactive disperse dye on silk fabric at pH 9 and 80°C yielded optimum color strength. The rate of dyeing on Nylon fabric was faster than that on PET fabric when both fabrics were dyed simultaneously in a dye bath, accordingly color strength of the dyed Nylon was higher. The reactive disperse dye can be applied for one-step and one-bath dyeing of N/P mixture fabric with good color fastness.     

Dyeing characteristics of Nylon,cotton and N/C mixture fabrics with reactive-disperse dyes containing a sulphatoethylsulphone group

The dyeing and color fastness properties of three reactive-disperse dyes containing a sulphatoethylsulphone group on Nylon, cotton and N/C mixture fabrics were examined. Reduction-clearing was more effective in removing the unfixed dyes than soaping since the reactive-disperse dye became hydrophobic during dyeing process. Nylon was dyed well with three reactive-disperse dyes at pH 5∼8 and difference in chemical structure between dyes did not affect the final color strength of the dyed Nylon fiber, but their build-up properties on Nylon were not so good. The color strength of the dyed cotton was not as high as that of Nylon. The color strength of cotton increased by lowering dyeing temperature when the reactive-disperse dyes having hydroxy group were used. Nylon absorbed more dye molecules than cotton in simultaneous dyeing, the color difference between Nylon and cotton could be reduced as the dyeing temperature decreased. N/C mixture fabric was dyed well at 60 °C with the reactive-disperse dyes having hydroxyl group when applied at pH 7 and 60 °C, and their build-up properties were good. It was also found that washing fastness and rubbing fastness of dyed Nylon, cotton and N/C fabrics with the reactive-disperse dyes were excellent, while light fastness was moderate.     

Colorimetric studies of benzoquinoline based hot brand monoazo reactive dyes and their dyeing performance on various fibers

A series of hot brand monoazo reactive dyes (9a-l) were obtained by the coupling of diazotized 1Hbenzo[ g]pyrazolo[3,4-b]quinoline-3-ylamine (5) with various cyanurated coupling components (8a-l) in good yield. Synthesized dyes were characterized by various spectroscopic techniques. Their dyeing performances as reactive dyes have been assessed on silk, wool, and cotton fabrics. The percentage dye bath exhaustion and fixation on different fibers were found to be very good. The dyed fabric showed moderate to very good light fastness and good to excellent washing and rubbing fastness properties. Spectral properties and colorimetric data of synthesized dyes have also been studied in detail.     

Study on the dyeing of wool fabrics with Phytolacca berry natural dyes

Dyeing of wool fabrics with natural dyes from Phytolacca berries has been studied. The effect of dye concentration, dye bath pH, dyeing time and temperature were discussed. The influence of chitosan application on the dyeing properties of wool fabrics was investigated. The SEM photographs of chitosan treated wool fabrics clearly depict the deposition of chitosan on the fibers. The effect of chitosan concentration, dye bath pH, dyeing time and temperature has been studied by orthogonal experiment. It has been proved that the dyed wool samples pretreated by chitosan have higher color fastness, faster dyeing rate, and better antibacterial properties compared with untreated ones.     

Study on the dyeing properties of hemicyanine dyes. I. Acrylic fabrics

Three hemicyanine dyes were employed in dyeing acrylic fabrics following traditional cationic dyeing procedures. The influence of the substituting groups of the dye molecule on the sorption rate and sorption isotherms was analyzed. The results showed that those dyed acrylic fabrics using hemicyanine dyes had obvious fluorescent effect in the spectra range 550–750 nm. In addition, according to the EN-471 standard (2003), the chromaticity of dyed acrylic fabric was calculated to evaluate whether hemicyanine dye could meet the requirements of the fluorescent dye for high visibility warning clothing.     

Synthesis of temporarily solubilized reactive disperse dyes and their application to the polyester/cotton blend fabric

Five temporarily solubilized reactive disperse dyes were synthesized and characterized. They were applied to polyester/cotton blend fabric using one-bath dyeing method without dispersing agent. The dye that has azonaphthalene chromophore seemed to not only be exhausted on polyester but also react with cotton. But other dyes were selectively dyed on polyester and showed limited uptake on cotton. Good levelling as well as moderate to good colour fastness was obtained with the dyes on P/C blend fabric.     

Properties of basic dyes on polyacrylonitrile treated m-aramid fabrics

Treatment of polyacrylonitrile (PAN) onto m-aramid fabric was carried out by pad-dry-cure method using dimethylformamide (DMF) dissolved acrylic fiber solution. The obtained PAN treated m-aramid fabric was dyed using exhaustion method with basic dyes. The effect of PAN treatment on fabric stiffness property was acceptable with acrylic fiber solutions ranging from 1 wt% to 4 wt%. Whilst, more than 4 wt% PAN treated fabrics exhibited undesirable stiffness. The dyeing results showed that PAN treated m-aramid fabrics exhibited a significant increase in color strength when compared to untreated fabric, arising from an increase in anionic dye sites (styrene SO₃ ^? group). Wash fastness was comparable to that of untreated fabric, indicating the strong interaction between dye molecules and the PAN. Rubbing fastness of treated fabrics was not affected by treatments with PAN concentrations lower than 4 wt%. Further increase in PAN concentration led to poorer rubbing fastness property due to the problem of surface dyeing. For light fastness, the PAN treatment failed to improve the light fastness property which is the main disadvantage of basic dyeing of aramid fabric. Finally, in case of PAN treatments with the range of 1 wt% to 4 wt%, the flame retardancy property of PAN treated m-aramid fabrics was found not affected by the percent add-on. However, above 4 wt% PAN treatment, the flame retardancy performance became deteriorated.     

Study on the natural dyeing of wool modified with enzyme

In this study, the natural pigment from sappan was used for the dyeing of wool fabrics after treatment with the protease and transglutaminase. The influences of protease and transglutaminase on the UV/visible absorption spectrum of aqueous extract of sappan were studied. The enzymatic modified wool was compared with non-modified wool in K/S value and fastness after direct dyeing and mordant dyeing. It was shown that protease and transglutaminase made the absorbance at the λ _max 540 nm in visible region increase. It suggested that there might be some interaction between the enzymes and sappan dye and the residual enzyme on wool fabric might affect the color of following dyeing. Compared to untreated wool, treatments with protease and transglutaminase enhance K/S value of wool dyed subsequently with sappan. Modification of protease led to some decrease in wet rubbing fastness, whereas transglutaminase had almost no influence on rubbing fastness. Enzymatic treatments have no influence on the washing fastness for samples dyed with sappan.     

New thiol-disulfide exchangers as anti-setting agents for wool fabric during dyeing

Setting of wool fabrics during dyeing is an acute industrial dilemma facing most of wool dyers. Therefore, wool fabrics were dyed with acid, basic, as well as mono- and bi-functional reactive dyes in the presence of selected aliphatic and aromatic anti-setting agents; namely 3,3-dithiodipropionic acid (DTDPA), dithiodiglycolic acid (DTDGA), 5,5-dithio-bis(2-nitrobenzoic acid) (DTBNBA), dithiodibutyric acid (DTDBA), 2,2-dithiodisalicylic acid (DTDSA), and 6,6-dithiodinicotinic acid (DTDNA). The effect of incorporating the said thiol/disulfide-exchangers into the dyeing bath of wool on its dimensional stability was assessed. The influence of the proposed anti-setting agents on the dyeability of wool with the said reactive dyes was monitored. The alteration in the chemical composition of the dyed fabrics was monitored by determining their sulfur and nitrogen contents, cysteine content, and the solubility degree in alkaline solution. The used reagents were found to be effective in stabilization of wool during dyeing with reactive dyes to different extents depending on the nature of the used anti-setting agent. Limited change in the chemical composition of the dyed samples was monitored without affecting their dyeability with the said dyes. The mechanism of interaction of these reagents with wool fabrics during dyeing was proposed.     

Ultrasound assisted extraction of natural dyes and natural mordants vis a vis dyeing

Most of the natural dyes require mordants for their fixation on textile materials. Natural mordants are thus gaining importance in order to get complete-natural dyeing. In the present work, natural dyes and mordants were extracted using conventional and ultrasound methods and comparative studies were made. The natural mordants namely harda and tamarind seed coat and natural dyes like turmeric, henna were extracted using conventional and ultrasound approaches and various extracts obtained were described in terms of their optical densities. In order to verify the extraction efficiencies, wool fabrics were dyed with extracts of various combinations of mordants/dyes and dyed fabrics were evaluated for their colour strengths and fastness properties. The extent of colour extraction was higher in case of ultrasound assisted extraction as compared to that of conventional method. The fabrics dyed using extracts of ultrasound method showed higher colour values as compared to those dyed using extracts from conventional methods thus confirming ultrasound as more efficient method of extraction.     

Reactive dyeing of meta-aramid fabrics photografted with dimethylaminopropyl methacrylamide

Aramid fibers have been known to difficult to dye with conventional dyes and dyeing techniques because of its extremely high crystallinity and compactness. In order to make the aramid fibers dyeable to a bright color in deep shade, meta-aramid fabrics were photografted under continuous UV irradiation with dimethylaminopropyl methacrylamide (DMAPMA) and benzophenone as a monomer and a hydrogen-abstractable photoinitiator respectively. Several factors affecting the photografting treatment of the meta-aramid fabrics were investigated including monomer and photoinitiator concentrations. ATR, ESCA and SEM analysis indicated significant alterations on the chemical structure and atomic composition of the photografted fabric surface and the fabric surface was covered with the grafted polymers. While the pristine meta-aramid fabrics showed no appreciable dyeability to the α-bromoacrylamide type reactive dyes, the grafted aramid fabrics showed the remarkably enhanced dyeability to the reactive dyes, which was proportional to the graft yield indicating the covalent bond formation between the dyes and the secondary amino groups in the grafted DMAPMA. In case of C.I. Reactive Red 84, a K/S value of 14.8 can be obtained with the grafted meta-aramid fabrics with a graft yield of 7.6 % (w/w). Also and the color fastness properties of the dyed fabrics was excellent in the conditions of washing, rubbing and solar irradiation.     

Novel cationic softener containing MCT reactive dyes for cotton: Simultaneous dyeing and functional finishing

The cationic softeners containing MCT (monochloro-s-triazinyl) reactive dyes were employed on the dyeing of cotton fabrics. The substantivity, exhaustion, and fixation of the dyes were investigated. It was found that these functional dyes could be effectively introduced to cotton fibers to achieve simultaneous coloration and functional finishing effects. All the dyed fabrics exhibited softening efficacy. The dyes offered excellent washing fastness on cotton substrate. Light fastnesses of the dyes on the substrate were poor.     

Dyeing properties of wool fabrics dyed with Vitis Vinifera L. (black grenache) leaves extract

In this work, water-extraction of Vitis Vinifera L. (Black Grenache) leaves and analysis of aqueous extracts for anthocyanins were investigated. Vegetable leaves were cultivated in North of Tunisia at different dates. Anthocyanins were identified as main constituents in these natural dyeing materials using high performance liquid chromatography (HPCL). Dyeability of wool and its fastness properties using Vitis Vinifera L. leaves extract were also determined. Aqueous extract of Vitis Vinifera L. leaves has markedly yielded shades with good fastness properties. Thus, affordability is a point favorable for Vitis Vinifera L. leaves. Effects of dye bath pH and temperature on dyeability and fastness proprieties of wool fabrics by aqueous extract of Vitis Vinifera L. leaves were evaluated. Experimental results showed that fastness properties of dyed fabrics ranged from average to very good. Vitis Vinifera L. leaves extracts showed potential to dyeing wool fibers under highly acidic conditions (pH ≤2). The results obtained here revealed that natural dyes extracted from Vitis Vinifera L. leaves can be cost-effective for dyeing wool fabrics.     

Salt-free dyeability of thiourea grafted cotton fabric

In this study salt-free dyeing cotton fabric was achieved by grafting thiourea to cotton fibers, where the thiourea grafted cotton fabric (TUGCF) was prepared by epoxidizing cotton fibers with epichlorohydrin in water and subsequently grafting in aqueous solution of thiourea. Fourier transform infrared spectra (FTIR) and XPS of the TUGCF indicated that a great amount of epoxy groups from the epoxidized cotton fibers reacted with amino groups from thiourea. The TUGCF fabric prepared at the optimum condition and subsequently dyed with reactive dyes in the absence of salt displayed significantly enhanced color strength, showing better dyeing properties when compared with the untreated cotton fabric dyed with conventional methods, in terms of washing fastness, rubbing fastness, and levelness. It was found that the dyeing performance of Reactive Red B-3BF followed a Langmuir-type adsorption curve when used to salt-free dye the TUGCF.     

UV-grafting coloration of cotton and wool fabrics using bismethacrylated quinizarin dye

A novel bifunctional quinizarin dye possessing two photoactive methacrylate groups was synthesized by the reaction of quinizarin with methacryloyl chloride. The synthesized dye, a low substantive dye under the conventional dyeing process, can be photografted onto cotton and wool fabrics at room temperature without neutral salts, which makes it a novel coloration process of excellent environmental friendliness. The concurrent polymerization and grafting of the synthesized dye onto cotton or wool can be assisted by a photoinitiator and acrylic acid in the case of cotton grafting. Moreover, color yields of the grafted fabrics improved significantly with the photografting of the bifunctional dye. The bifunctional dye can be photopolymerized with the increase in UV energy to 25 J/cm² and the oligomeric dye has a degree of polymerization of 5 or more. Furthermore, the color fastness properties of the grafted fabrics were superior to those of the dyed fabrics via exhaustion.     

Dyeing and fastness properties of vat dyes on meta-aramid woven fabric

meta-Aramid fibers have an excellent heat-resistant property and are widely used for protective clothings such as fire-fighter suit and racing suit. They can also be used as military uniforms such as flight suit or army uniform. Vat dyes are specially used for military uniforms owing to outstanding fastness properties, earth tone shade, and near infrared (NIR) camouflage. In this study, 100 % meta-aramid woven fabric was dyed with three vat dyes using an exhaustion method and their dyeing and fastness properties were investigated. Color yields of the vat dyes on the meta-aramid fabric were found to be dependent upon dyeing temperature, liquor ratio, amount of reducing agent, and amount of salt. Dyeing behavior of the vat dye on the meta-aramid fiber was very similar to that on cellulose fibers. It was found that the meta-aramid fabric dyed with 1% owf of C.I. Vat Green 1 satisfied the tolerance of the reflectance spectrum of forest green color in the Korean military standard. Thermal stability and mechanical property of the meta-aramid fabric did not significantly affected by the vat dyeing process. Wash and perspiration fastness was generally good but rubbing and light fastness was unsatisfied.     

Acrylamide assisted photoinitiator-free photografting of acrylamido dyes onto wool

Upon UV irradiation wool fabrics can be photografted with photoactive acrylamido dyes at room temperature without photoinitiaors, which is eco-friendly coloration process compared with conventional adsorption-based dyeing. Acrylamide addition as a comonomer can improve the photografting probably by reducing the steric hindrance between the bulky dyes during the photocopolymerization. Even without photointiators and neutral salts, the optimal K/S values of the photografted wool reached upto 18.7 and 18.5 for Reactive Red 84 and Yellow 39 dyes respectively. The optimal UV-grafting coloration can be achieved when a UV energy of 25 J/cm² was irradiated on the padded fabrics with 6.3 %owf dye containing 0.65 mole ratio of acrylamide to the dyes. Furthermore, the color fastness of the grafted fabrics was as good as those of conventionally dyed fabrics due to the copolymerization of dyes and comonomers.