Sulphur Dyes Research Articles

The Influence of Fibre Content of Knitted Fabric on the Ultraviolet Radiation Protection Property

In this study, sulphur dye was used for dyeing 100% cotton knitted fabric and the effect of dye concentration and colour shade on ultraviolet protection factor (UPF) was discussed. The results indicated that the UVR absorbency of sulphur dye was not satisfactory. Generally speaking, the higher the dye concentration, the darker the shade of fabric. Nevertheless, it did not affect the UPF of fabric if the absorbency of the selected dye was ineffective.

The Comparison between a Natural Reducing Agent and Sodium Dithionite in Vat, Indigo and Sulphur Dyeing on Cotton Fabric

In recent years, the use of low-environmental impact biotechnology giving rises to new types of treatment in the textile industry. From the environmental point of view, particularly the textile dyeing process constitutes a major pollution problem due to the variety and complexity of chemicals employed. In most industrial vat and indigo, sulphur dyeing processes, all of them are reduced mainly using sodium dithionite. This process produces large amounts of hazardous by-products which increase the costs for waste water treatment. Hence, many attempts are being made to replace the environmentally unfavorable sodium dithionite by ecologically more attractive alternatives, such as organic reducing agents or catalytic hydrogenation and natural reducing agent. In this paper ,a natural reducing agent is introduced that comes from a plant and have been studied on the substance for comparison it with sodium dithionite on vat, indigo and sulphur dyeing on cotton fabrics. The color strength of the samples was analyzed by Reflective Spectrophotometer and the color fastness of them was investigated. The results show that, the use of natural reducing agent in natural indigo dye and sulphur dye is better and for the rest of them has almost good advantage, but it cannot reduce synthetic indigo as well as sodium dithionite. Therefore, with introducing the substance, consumption of chemicals is minimized and vat, indigo and sulphur dyeing should be environmental.

Short-Flow and High-Efficiency Dyeing Process of Sulfur Black on Cotton Fabrics

Cottons dark-dyeing with sulfur black was studied in this paper. Its a simple process for cotton because of no bleaching, just only desizing, scouring and dyeing with two steps in one-bath. Through adjusting technical parameters, the optimum conditions were obtained: NaOH 6 g/L, Na2SiO3 2 g/L, scouring agent 2 g/L, JFC 1 g/L, sulfur black 14%, Na2S 16%, carbamide 2 g/L, bath ratio 1:20, scouring and dyeing at 95 °C for 45 min and 35 min separately. Compared the simple process with the traditional one, the former can get similar performance on dyeing. In addition, the simple process showed such advantages as short time, high efficiency, reduced energy consumption, relatively low water consumption and reduced sewage emission.

Electrochemical Techniques in Textile Processes and Wastewater Treatment

The textile industry uses the electrochemical techniques both in textile processes (such as manufacturing fibers, dyeing processes, and decolorizing fabrics) and in wastewaters treatments (color removal). Electrochemical reduction reactions are mostly used in sulfur and vat dyeing, but in some cases, they are applied to effluents discoloration. However, the main applications of electrochemical treatments in the textile sector are based on oxidation reactions. Most of electrochemical oxidation processes involve indirect reactions which imply the generation of hypochlorite or hydroxyl radical in situ. These electrogenerated species are able to bleach indigo-dyed denim fabrics and to degrade dyes in wastewater in order to achieve the effluent color removal. The aim of this paper is to review the electrochemical techniques applied to textile industry. In particular, they are an efficient method to remove color of textile effluents. The reuse of the discolored effluent is possible, which implies an important saving of salt and water (i.e., by means of the “UVEC Cell”).

Dyeing wool with a sulphur black dye using a sodium borohydride /sodium bisulphite reducing system

Sulphur dyes have been traditionally used for dyeing cellulosic materials, in particular for dark navy and black shades on cotton. This study investigates the feasibility of using the dyestuff CI Sulphur Black 1 as a cost‐effective, metal‐free alternative to reactive and chrome dyes, to produce deep black shades on wool with high fastness levels. The new wool dyeing procedure uses sodium borohydride and sodium bisulphite as the reducing system for the sulphur dyes. Results are presented on the colour parameters, fastness to washing, alkaline perspiration, light, dry and wet rubbing, and wet burst strength of wool fabrics after dyeing with the sulphur dye. The results have been compared with those of wool dyed by conventional methods with a chrome black and a reactive black dye. It has been shown that the sulphur dye can be used to produce a deep black shade on wool that is comparable with that obtained with either a reactive or chrome black dyestuff. With the exception of wet rubbing, the fastness properties are generally similar, or better than, those of the reactive and chrome dyes, but fibre damage is greater. Some further work is therefore required to overcome these two disadvantages.

Dyeing Natural Cellulose Fibers from Cornhusks: A Comparative Study with Cotton Fibers

This research shows that natural cellulose fibers extracted from cornhusks have better dyeing properties for direct and sulfur dyes and similar dyeing properties for reactive and vat dyes compared ...

Crossflow microfiltration using ceramic membrane for treatment of sulphur black effluent from garment processing industry

Crossflow microfiltration (CMF) using ceramic membrane, developed from a low cost composition of α-alumina and clay in the tubular multichannel configuration with filtration area of 0.045 m 2 was used alone, and in combination with different physicochemical techniques, viz. adsorption and chemical coagulation for treatment of wastewater collected from the sulphur dyeing process of a garment processing industry. The concentrated effluent was enriched with sulphur black dye, with turbidity 5912 NTU and COD of 3910 mg/l. Adsorptive treatment was carried out using a biosorbent prepared from the roots of an aquatic weed, E. Crassipes. Chemical pretreatment was carried out using different inorganic coagulants. Effect of different transmembrane pressures (TMP) in the range of 0.4–1.2 kg/cm 2 was observed and constant pressure filtration was conducted at 1 kg/cm 2 TMP. Performance of the single stage CMF process was compared with that of two-stage processes in terms of the permeate quality, viz. COD, color, turbidity and TSS etc. and permeate flux. Encouraging result was found after microfiltration of the biosorbent treated feed as well as, effluent pretreated with aluminium sulphate. Dye removal was about 99%, with 80% reduction of COD. The chemical pretreatment process considerably increased the permeate flux compared to the single stage process.

Preparation and characterization of novel copoly (phthalazinone ether sulfone) ultrafiltration membranes with excellent thermal stability

Novel copoly (phthalazinone ether sulfone) (PPBES) UF membranes with excellent performance were prepared with phase inversion method. The types of solvent, the effects of PPBES concentration, EGME concentration and coagulation temperature on the morphologies and performances of UF membrane were investigated in detail. The structures of the membrane were characterized by scanning electron microscope (SEM). With the increase of EGME concentration in the casting solution, the morphologies of the UF membrane changed from finger-like structure to sponge-like structure. The thermal stability of the PPBES UF membranes prepared in this work was investigated with Sulfur Black B dye solution. When the temperature of feed solution was raised from 20 to 95 °C, the permeation flux increased more than three times while the rejection change was not observed.

Desalination of dye utilizing copoly(phthalazinone biphenyl ether sulfone) ultrafiltration membrane with low molecular weight cut-off

Copoly(phthalazinone biphenyl ether sulfone) (PPBES) ultrafiltration (UF) membrane with low molecular weight cut-off (MWCO) possesses excellent thermal resistance and it is suitable to be utilized in dye wastewater treatment at high temperature. The rejection of polyethylene glycol (PEG1000) of the membrane was 100% while the flux was 232 L/m 2 h at 20 °C and 0.2 MPa. It was showed that the rejections of NaCl and Na 2SO 4 were both 0%. The rejections of Congo Red (Direct Dye), Sulfur Black B (Sulfur Dye) and Gentian Violet (Anionic Dye) were all 100% while the rejections of C. I. Reactive Yellow 86 (Reactive Dye), C. I. Disperse Red 73 (Disperse Dye) and Acid Chrome Blue K (Cationic Dye) were 79%, 54% and 43%, respectively. The fluxes of the membrane during treatment were all higher than 87 L/m 2 h at 20 °C and 0.2 MPa except for C. I. Disperse Red 73. Effect of inorganic salt concentration on membrane performance was investigated. Thermal resistance of the membrane was also evaluated with Sulfur Black B. It was found that the flux increased 4.5 times while the rejection did not decline when the operation temperature was raised from 20 °C to 95 °C. The membrane ran 20 h at 90 °C without the membrane performance decline which showed that the membrane had good thermal resistance.

The dyeing of silk Part 1: Low temperature application of solubilised sulphur dyes using sodium thioglycolate

Four C.I. Solubilised Sulphur dyes were applied to cultivated silk fabric using sodium thioglycolate at pH 7, for 30 min at 60 °C in the absence of electrolyte. Medium/deep shades were obtained that displayed good/excellent fastness to washing at 40 °C and little or no sensitivity to oxygen bleach fading. The dry rub fastness of the dyeings ranged from moderate to good whilst the wet rub fastness varied from poor to moderate; light fastness of the 10% omf dyeings varied from low to moderate. The mild application conditions used had little effect on the tensile strength of the fabric.

Electrochemical characteristics and dyeing properties of selected 9,10-anthraquinones as mediators for the indirect cathodic reduction of dyes

Substituted 9,10-anthraquinones were characterised using cyclic voltammetry for their potential to serve as mediators for the indirect cathodic reduction of dispersed sulphur dyes, vat dyes and indigo. Besides characterisation of the electrochemical behaviour, the compounds were assessed in model dyeing experiments for chemical stability and staining of cotton fabric. 1,2-, 1,4- and 1,8-dihydroxy-9,10-anthraquinones exhibited negative mid-point potential ((E p) d + (E p) a)/2 of −713 to −820 mV (vs. Ag/AgCl, 3 M KCl). Under model dyebath conditions staining of cotton fabric occurred. 9,10-anthraquinone-1,5-disulfonate and 9,10-anthraquinone-2,6-disulfonate both imparted low staining to cotton; their mid-point potentials (−698 mV and −475 mV, respectively) limit their applicability to the reduction of sulphur dyes. Dihydroxy substituted 9,10-anthraquinone-sulfonates exhibited low staining owing to their good solubility. The mid-point potentials of 1,4-dihydroxy-9,10-anthraquinone-2-sulfonate and 5,8-dihydroxy-9,10-anthraquinone-2-sulfonate were only −618 mV and −675 mV respectively. Of the 9,10-anthraquinoids studied, 1,2-dihydroxy-9,10-anthraquinone-3-sulfonate (C.I. Mordant Red 3) could be identified as the most promising reversible redox couple, displaying a mid-point potential of −848 mV, low staining of cotton fabric and sufficient chemical stability under dyebath conditions.

Improving the Resistance of Sulfur Dyes to Oxidation

A method that substantially improves the oxidative bleaching resistance of sulfur dyed textiles is reported. Sulfur dyes are known for their poor bleaching resistance due to the sensitivity of the sulfur linkages to oxidation. This disadvantage severely prohibits the broad application of sulfur dyes because of the existence of the activated oxidative bleaching agents in many commercial detergents. In this study, 1% (w/w) of lanthanum triacetate was applied to sulfur dyed cotton fabrics via a simple padding procedure to chemically stabilize the sulfur linkages. The treatment could render sulfur dyed cotton fabrics a reduction in color changes of about 50% after laundering with detergent containing a bleaching agent, an improvement in strength retention of almost 100% after aging and an improvement in staining resistance of at least 0.5-class for about 1/3 of the sulfur dyes examined. These improvements were proved durable to repeated launderings.

Pad Dyeing of Blue Sulphur Dyes Oxidized by Hydrogen Peroxide

Pad Dyeing of Blue Sulphur Dyes Oxidized by Hydrogen Peroxide

On the Colour Change of Sulfur Dye by Soaping

On the Colour Change of Sulfur Dye by Soaping

Synthesis and modification of sulfur dyes

An integrated approach to sulfur utilization by synthesis of sulfur dyes derived from m- and p-phenylenediamine was suggested. The sulfur dyes obtained were modified by the reaction with butyl bromide. The possibility of dyeing cotton fabrics by the dyes prepared was examined, and the coloration fastness was evaluated.

Model calculations to optimise multi-cathode flow through electrolysers: direct cathodic reduction of C.I. Sulphur Black 1

A laboratory cell equipped with multiple porous electrodes connected electrically in parallel and hydrostatically in series was used to reduce dispersed Colour Index (C.I.) Sulphur Black 1 to synthesise C.I. Leuco Sulphur Black 1. At higher cell current bipolar effects limit the maximum thickness of a porous cathode element. A mathematical model has been established to estimate the maximum thickness of a cathode element. The cell voltage can be calculated using a simple resistor network. The presented model calculations permit optimisation of a cell with multiple porous electrodes with regard to dimensions, cell costs and energy consumption. A multi-cathode cell, equipped with 10 cathodes for a total cell current of 10 A, was used to study production of highly concentrated C.I. Leuco Sulphur Black 1 solutions. Compared to chemical reduction, dyeing behaviour was found to be independent of reduction method used.

Treating sulfur black dye wastewater with quaternized poly (phthalazinone ether sulfone ketone) nanofiltration membranes

Two kinds of nanofiltration (NF) membranes were investigated in treating the Sulfur Black B dye wastewater. Negatively charged polypiperazine amide/poly (phthalazinone ether sulfone ketone) (PIP/PPESK) NF membrane was prepared by interfacial polymerization method while positively charged quaternized poly (phthalazinone ether sulfone ketone) (QAPPESK) membrane was prepared by phase inversion method. QAPPESK NF membrane was selected for further study because it performed higher dye rejection and flux compared with the PIP/PPESK NF membrane. The effects of different operation conditions were systematically studied based on the rejection and desalination of the dye. Over 14.5 L/m 2 h flux, 92.3% dye rejection and 10% salts rejection were observed in the long term operation at 60 °C which indicated that the QAPPESK membranes could be successfully applied in the sulfur black dye wastewater treatment and inorganic salts reuse.

Improving the Environmental Aspects of Sulphur Dyeing of Cotton Knitted Fabrics

ABSTRACT An attempt has been made to search for an eco-friendly reductants and oxidants for complete substitution of the hazardous ones along with finding out proper conditions for attaining better knitted sulphur dyeings. The results detailed in this article indicate that a) the extent of coloration is governed by both the type of reductant as well as dye/reductant ratio, i.e. liquid glucose (LG, ratio 1/1) > glucose (G, ratio, 1/1) > molaas (M, ratio 1/4), as well as the knitted fabric structure i.e. Pique > Rib > Milton; (b) the depth of shade can be improved by raising the dyeing temperature up to 80°C for 45 min., at a material-to-liquor ratio 1/10, in presence of 30g/l common salt; (c) the extent of sulphur dyeing is determined by the nature of oxidant, i.e. (NH4)2S2O8 > H2O2 > None; (d) after treatment with cationic softener results in higher softness along with better washing and rubbing fastness; and (e) the dyeing as well as fastness properties of the obtained sulphur dyeings depend on the sulphur dye category.

Potential Applications of Oxidoreductases for the Re‐oxidation of Leuco Vat or Sulfur Dyes in Textile Dyeing

AbstractConventional textile dyeing by vat and sulfur dyes includes reduction and re‐oxidation steps (with chemical reductants and oxidants), so that the insoluble dyes can be solubilized in the dyeing solution, adsorbed by the fabric, and fixed onto the dyed fabric. The treatments often involve hazardous chemicals, expensive catalysts, or conditions that are suboptimally effective, energy‐intensive, caustic, or polluting. Improving these steps with enzyme technology could be of significant interest in terms of better dyeing, handling of hazardous chemicals, disposal of waste, or production economy. The idea of an enzymatic re‐oxidation step for vat and sulfur dyeings was tested under simplified laboratory conditions. Selected vat and sulfur dyes, including Vat Blue 43, Vat Orange 7, Vat Green 3, Vat Orange 2, Vat Red 13, Vat Yellow 2, and Sulfur Black 1, were first chemically reduced. The reduced (leuco) dyes were then re‐oxidized by aerated buffer solutions or H2O2, in the presence or absence of an oxidoreductase, selected from seven laccases from Myceliophthora thermophila, Scytalidium thermophilum, Coprinus cinereus, Trametes villosa, Rhizoctonia solani, Pycnoporus cinnabarinus, Botrytis cinerea, a bilirubin oxidase from Myrothecium verrucaria, and a heme peroxidase from Coprinus cineresu. It was shown that the enzymes were able to catalyze and accelerate the re‐oxidation of the reduced dyes, even when they were adsorbed on cotton fabric, by dissolved air (O2) or H2O2. Small redox‐active mediators could facilitate the enzymatic re‐oxidation. For Sulfur Black 1, a higher conversion of the leuco dye was achieved with laccase‐catalyzed re‐oxidation. The further development of this potential enzyme application is discussed.

Principles of an approach for coloring military camouflage

Optimum technology for dyeing serge with water-soluble sulfur dyes by the continuous pad-steam method was developed. It was shown that the colors for the background obtained in dyeing with Thiosol Olive and Diresul Olive-green satisfy camouflage requirements only in the daytime. Optimum technology for dyeing serge with Active Olive Special by continuous pad-steam and pad-thermofixation methods was developed. The background colors obtained in dyeing with Active Olive Special ensures camouflage both in the visible and in the IR region of the spectrum.