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The conventional textile dyeing process requires various operational characteristics, and determining the most reliable factor in dyeing performance has always been a challenge for the textile industry. Thus, the present paper aimed to evaluate the process sensitivity of C. I. Reactive Blue 194 dyeing of cotton fabric using a statistical technique.

An L₂₇ orthogonal array-based Taguchi's methodology was used with six parameters and three levels of each parameter. The signal-to-noise (S/N) ratio and analysis of variance were studied using total fixation efficiency (T%) as the response of the process sensitivity.

Results showed that dyebath pH was the most influential factor on the process and total fixation efficiency (p-value = 0.00 and contribution percentage 45.03%), followed by dye-fixing temperature, dye mass, electrolyte concentration, dye-fixing time and material to liquor ratio.

Overall this study provides a foundation for the determination of dyeing process sensitivity that will be useful in textile industries toward further development.

An indirect electrochemical reduction and dyeing with indigo were carried out here to solve problems of low dye reduction rate and poor dyeing depth in the current electrochemical dyeing process.

Response surface analysis tests were performed to evaluate the effects of ferrous sulfate concentration, medium concentration, sodium hydroxide concentration and reduction time on the reduction efficiency of indirect electrochemical reduction of indigo.

The conditions obtained by design-expert optimization showed that the concentration of FeSO₄·7H₂O has the most significant effect on the reduction performance of dye liquor. Under the optimized electrochemical reduction dyeing process, the rate of dye reduction could be reached 91.21 per cent and the K/S value of indirect electrochemical dyeing of indigo can be achieved to 12.96, which is increased by about 9.56 per cent compared with that of Na₂S₂O₄ dyeing with the same color fastness basically.

The recyclability and biodegradability of the dye remain to be explored.

The strategy presented here can be developed to replace a substantial part of electrochemical dyeing with optimized product quality and reduced environmental pollution in denim production.

The strategy presented here can be developed to replace a substantial part of electrochemical dyeing with optimized product quality and reduced environmental pollution in denim production.

Application of the Fe(II)-DGS-Abal B complex media system in the indirect electrochemical reduction of indigo.

In this study, the foam dyeing technology was applied to dye cotton knitted fabric for achieving the surface-dyed result. The T-shirt made by this surface-dyed fabric could easily obtain the wash-out effect after garment laundering. The pigment dyeing performances in foam dyeing were system studied. Colour strength, colourfastness and serviceability of fabrics dyed with the methods of foam-padding and liquid-padding were evaluated and compared. Results show that surface dyeing for cotton-knitted fabric with foam media could overcome the shortcoming of poor penetration in foam dyeing method, and turn the poor penetration into the superiority for obtaining the surface-dyed result. The serviceability such as water absorption and handle property was also well improved in foam dyeing method. Finally, the advantages of energy saving and reducing chemical usage were implemented throughout the dyeing process.

The purpose of this study reported in this paper was to find the correct Mt/M₈ and Dt/a² data lists of Hill Formula. This paper enumerates several kinds of Hill formula data lists presented in different literatures, and the authors hope to draw the correct conclusion.

The eight different forms collected in the research project were compared. The mathematician was asked to give a suggestion from a professional point of view and to arrive at a conclusion.

In all eight cases, the third, the eighth and seventh cases are consistent and are considered reasonable and correct.

First-hand information was not used because of unavailability of the earliest published version of the Hill formula.

It is helpful to the correct application of Hill formula and the calculation of diffusion coefficient. It is also valuable to the study of dyeing kinetics.

The research helps to reduce and avoid the confusion in the application of Hill formula in dyeing kinetics research.

Pitting inhibition efficiency of SO₄⁻ and NO₃⁻ on AISI 316L stainless steel in contact with Cl⁻-containing fiber dyeing solutions together with the influence of the anions on absorption behavior of the solutions were investigated. The purpose of the study is to experimentally determine an optimized dyeing solution efficient on both – inhibition of the steel’s pitting and exhaustion of the dyes dissolved.

Methods such as electrochemical cyclic polarization, UV-visible range spectrophotometry and scanning electron microscopy have been used to assess the performance of two inhibitors on both pitting inhibition of the steel and dissolving ability over the reactive dyes. To find out a promising dyeing solution mixture in both aspects, Cl content of the original dyeing solution was replaced gradually with the inhibiting anions, where the total anionic content was kept constant to unchange the dye exhaustion potential of the solution. Then, those solutions came out with diverse pitting inhibition, and dye absorption levels were compared together for reducing/avoiding the pitting issues of the reactive dyeing vessels of the industry.

Rather high absorption levels detected by visible range spectrophotometry on the solutions showing sound inhibition levels indicated possibility of unaltered reactive dyeing qualities with an enhanced vessel lifetime as the inhibitive anions replace Cl⁻. Nitrate performed better than sulfate both on inhibition and absorption in the dyeing solutions. Also, 316L vessels became open to an extra anodic protection in inhibitor added solutions.

The findings are valid for a certain group of reactive dyes and dyeing solutions held at 70°C. However, the testing methods are available to almost any dyeing solution and dyeing temperature.

The work presents a combined testing of pitting inhibition and absorption behavior of dyeing solutions involving Cl⁻ that has not been reported so far. It shows that solution recipes least harmful to the steel vessels can be outlined for various reactive or other types of dye groups.

To improve the problems as the heavy burden of sewage treatment and environmental pollution caused by the traditional sodium hydrosulfite reduction dyeing of indigo, this study aims to carry out the direct electrochemical reduction dyeing for indigo with the eco-friendly Cu(II)/sodium borohydride reduction system under normal temperature and pressure conditions.

The electrochemical behavior of Cu(II)/sodium borohydride reduction system was investigated by cyclic voltammetry. And, the dyeing performance of the Cu(II)/sodium borohydride reduction system was developed by optimizing the concentration of copper sulfate in the anode electrolyte, applied voltage and reduction time via single-factor and orthogonal integrated analysis.

The dyeing performance of the Cu(II)/sodium borohydride reduction system is superior to that of the traditional reduction dyeing with sodium hydrosulfite. In the case of the optimized condition, the soaping fastness and dry/wet rubbing fastness of the dyed fabric in the two reduction dyeing processes were basically comparable, the K/S value of electrocatalytic reduction of indigo by Cu(II)/NaBH4 is 11.81, which is higher than that obtained by traditional sodium hydrosulfite reduction dyeing of indigo.

The innovative electrocatalytic reduction system applied herein uses sodium borohydride as the hydrogen source combined with Cu(II) complex as the catalyst, which can serve as a medium for electron transfer and active the dye molecule to make it easier to be reduced. The electrochemical dyeing strategy presented here provides a new idea to improve the reduction dyeing performance of indigo by sodium borohydride.

Textile industry is considered to be one of the largest consumers of water. There needs to be an alternative for water in textile wet processing. Solvent dyeing can be an approach to replace the use of water in dyeing for water conservation.

In this study, the dyeing of polyester was carried out using conventional and solvent dyeing methods. The solvent used was non-aqueous, deep eutectic solvent (DES) prepared using choline chloride and urea. Dyeing parameters such as time, temperature and pH were optimized for a concentration of dye using the solvent and were compared with the conventional dyeing.

The prepared solvent was characterized in terms of Fourier-transform infrared resonance and ¹H and ¹³C nuclear magnetic resonance to analyze the reaction between choline chloride and urea. Dyeing performance in terms of K/S and fastness properties of dyed fabrics were evaluated and found to be at par against conventional dyeing.

Use of DES as a dyeing medium is a novel approach in the textile industry.

The purpose of this paper is to explore a new eco-friendly green textile dyeing. Natural plant Buddleja officinalis is traditionally used as yellow pigment addition in rice. It is worth developing its application and dyeing performance in cotton fabric.

Buddleja officinalis dried flower was extracted with ethanol aqueous. The extraction conditions including ethanol concentration, material to liquor ratio, extract time and temperature were optimized. Then cotton fabrics were dyed with Buddleja officinalis extraction under conventional and ultrasonic conditions. The effects of dyeing time, bath ratio, pH value of dyeing bath, dyeing temperature and mordants on K/S values were studied and the resulting color strength obtained by conventional and ultrasonic dyeing were compared. The ultraviolet (UV) transmittance of Buddleja officinalis dyed cotton fabric was also evaluated.

The color strength of the fabric dyed with Buddleja officinalis under ultrasonic conditions was higher than that under conventional conditions. Alum, Fe and Cu as simultaneous mordants improved the K/S value of the dyed cotton fabrics. Both washing fastness and rubbing fastness were fairly good in all Buddleja officinalis dyed cotton fabrics, washing fastness = 3–4 and rubbing fastness = 4. What’s more, the dyed cotton fabrics showed lower transmittance values as compared to undyed cotton fabrics and indicated potential UV protection capability.

Buddleja officinalis can be a new natural dye source for the ultrasonic dyeing of cotton fabric.

It is for the first time that Buddleja officinalis is used as a natural dye in cotton fabric dyeing with less water and the dyeing using ultrasound has been found to have an obvious improvement in the color strength and color-fastness.

This paper aims to find a suitable solution to degrade the C.I. Reactive Red 24 (RR24) dyeing wastewater by using sodium persulphate to recycle water and inorganic salts.

The effects of temperature, the concentration of inorganic salts and Na₂CO₃ and the initial pH value on the degradation of RR24 were studied. Furthermore, the relationship between free radicals and RR24 degradation effect was investigated. Microscopic routes and mechanisms of dye degradation were further confirmed by testing the degradation karyoplasmic ratio of the product. The feasibility of the one-bath cyclic dyeing in the recycled dyeing wastewater was confirmed through the properties of dye utilization and color parameters.

The appropriate conditions were 0.3 g/L of sodium persulphate and treatment at 95°C for 30 min, which resulted in a decolorization rate of 98.4% for the dyeing wastewater. Acidic conditions are conducive to rapid degradation of dyes, while ·OH or SO₄⁻· have a destructive effect on dyes under alkaline conditions. In the early stage of degradation, ·OH played a major role in the degradation of dyes. For sustainable cyclic dyeing of RR24, inorganic salts were reused in this dyeing process and dye uptake increased with the times of cycles. After the fixation, some Na₂CO₃ may be converted to other salts, thereby increasing the dye uptake in subsequent cyclic staining. However, it has little impact on the dye exhaustion rate and color parameters of dyed fabrics.

The recommended technology not only reduces the quantity of dyeing wastewater but also enables the recycling of inorganic salts and water, which meets the requirements of sustainable development and clean production.

Based on clarifying the structural difference between jade fibre and general polyester fibre, this paper aims to study the dyeing properties and dyeing adsorption mechanism of jade fibre with disperse dye and cationic dye.

The chemical structure and microstructure of jade fibre were briefly explained comparing with ordinary polyester fibre. The dyeing rate curve and dyeing adsorption isotherm of disperse dyes and cationic dyes on jade fibre were, respectively, studied. The dyeing uptake, dyeing absorption mechanism, and the main dyeing process parameters were proposed.

Jade fibre can be dyed with cationic dye and disperse dye. The suitable exhaust dyeing process is 110°C and 40 minutes for disperse dye, 100°C and 60 minutes for cationic dye. The dyeing uptake on jade fibre with both disperse dyes or cationic dyes is much higher than that on general polyester fibre and acrylic fibre, and the dyeing adsorption mechanism belongs to the combination of Langmuir and Nernst adsorption for disperse dyes and Langmuir adsorption for cationic dyes. Comparing with ordinary polyester fibre, jade fibre has the advantage of low temperature dyeing and reduced effluent, as is significant to energy-saving and emission reduction.

Jade fibre is a new type of modified polyester fibre with the function of health protection and energy conservation. There are little technical data in the literature at present about the dyeing property of jade fibre.