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1 – 10 of 480Quratulain Mohtashim, Salma Farooq and Fareha Asim
The application of indigo dyes in the denim industries has been criticised due to the introduction of non-renewable oxidation products into the environment. Previous studies have…
Abstract
Purpose
The application of indigo dyes in the denim industries has been criticised due to the introduction of non-renewable oxidation products into the environment. Previous studies have investigated that reducing sugars can be used as green alternatives to sodium dithionite in the indigo dyeing of cotton fabric owing to their reduced and stable redox potential in the dye bath. The purpose of this study was to dye denim cotton fabric with indigo dye using various reducing sugars and alkalis. The use of sucrose and potassium hydroxide (KOH) for indigo dyeing has been explored for the first time.
Design/methodology/approach
A mixed factorial design with four variables including alkali, pH, number of dips and type of reducing sugar at different levels was studied to identify a significant correlation between the effect of these variables on the colour strength and fastness properties of the dyeings.
Findings
Investigations were made to examine the significant factors and interactions of the selected responses in the eco-friendly dyeing method. This process has the potential to reduce the load of sulphite and sulphate generated in the dyebath due to the use of a conventional reducing agent, sodium dithionite. The colour strength of the dyeing reduced with fructose was found to be better than other reducing sugars and significantly influenced by the number of dips, pH levels and the interaction between pH and reducing sugars. Using fructose for indigo dyeing with two dips at a pH of 11.5, using KOH as an alkali, results in higher colour strength values. The fastness properties of the indigo-dyed sample with reducing sugars ranging from fair to good or good to excellent. Specifically, colour change receives a rating of grey scale 3–4, staining 4–5, dry rubbing 4 and light fastness 3–4. These assessments hold true across various factors such as the type of reducing sugar, alkali, pH and the number of dips. The optimised parameters leading to improved colour strength and fastness properties are also discussed.
Originality/value
This dyeing technique is novel and a green alternative to dithionite denim dyeing. This process is found to be useful for indigo dyeing of denim fabric leading to reduced and stable redox potential in the dyebath and acceptable colour strength of the dyed fabric.
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Tulsi Jayakumar and Vineeta Dwivedi
The learning outcomes of this study are as follows:▪ to analyze service attributes that influence customers’ decisions to purchase services;▪ to identify the factors that…
Abstract
Learning outcomes
The learning outcomes of this study are as follows:▪ to analyze service attributes that influence customers’ decisions to purchase services;▪ to identify the factors that influence customers’ perceptions of service quality;▪ to identify the “moments of truth” that the service provider (IndiGo) would need to monitor and manage through the service encounter; and▪ to use the Servuction model to analyze the various elements of the service process.
Case overview/synopsis
In May 2022, the chief executive officer of IndiGo Airlines - India’s largest passenger airline by market share, Ronojoy Dutta, faced flak over the airline staff's handling of a specially abled child travelling with his parents on IndiGo Airlines. The staff member, reacting to the tantrums of the disturbed child, had refused to allow the boy and his parents to board the flight. He had cited the “risk to other passengers” from the boy as the reason for such a refusal (Biswas, 2022). In spite of the boy’s parents being supported by their fellow passengers, the IndiGo staff member refused to relent, and the flight took off without the trio (Firstpost, 2022). The incident goes viral when a fellow flyer shares a Facebook post describing it first-hand and provokes widespread condemnation of the nation's “preferred airline” (IndiGo, 2023) by citizens and politicians on various social media platforms besides Facebook (Gupta, 2022). Dutta initially supports his employee even as he issues a statement expressing his regret at the “unfortunate incident” (Business Standard, 2022a). The regulatory body for aviation in India, the Directorate General of Civil Aviation, imposes a fine of INR 5 lakh on IndiGo for denying boarding to a specially abled child (Indian Express, 2022). How could an incident like this impact the perception of IndiGo’s service quality? How could Dutta better ensure that IndiGo managed the various touch points with the customer over the entire service encounter – the “moments of truth”? How could he prevent such a fiasco in the future, ensuring that IndiGo remains India’s “preferred airline”?
Complexity academic level
This case is intended to be taught in an undergraduate or MBA marketing course in a module on service marketing. The case can also form a 90-min module in a service marketing course within an advanced management or executive education program.
Supplementary materials
Teaching Notes are available for educators only.
Subject code
CCS 8: Marketing.
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Xiaoyan Li, Zhihui Zhang, Jiming Yao, MengQian Wang and Na Yang
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…
Abstract
Purpose
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.
Design/methodology/approach
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.
Findings
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.
Originality/value
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.
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Saima Habib, Zulfiqar Ali Raza, Farzana Kishwar and Sharjeel Abid
This paper aims to develop an indigo-dyed denim fabric treated with a nanosilver colloid in the presence of a natural crosslinker of citric acid for possible surgical gown…
Abstract
Purpose
This paper aims to develop an indigo-dyed denim fabric treated with a nanosilver colloid in the presence of a natural crosslinker of citric acid for possible surgical gown fabrication applications.
Design/methodology/approach
A bleached denim fabric was dyed with the sustainable indigo dye followed by silver nanofinishing through citric acid crosslinking under the pad-dry-cure method. The prepared denim samples were analyzed for chemo-physical, textile, dyeing, antibacterial and finish release properties.
Findings
The results demonstrated that the comfort and textile characteristics of nanosilver-treated/indigo-dyed cellulosic fabric were affected due to the crosslinking, surface amphiphilicity and air permeability. These properties were, still, in the acceptable range for the fabrication of naturally dyed and antibacterial nanofinished denim gowns.
Practical implications
The dyeing of denim with synthetic dyes may cause harmful effects on the skin and health of the wearer, and the authors present an eco-friendly sustainable approach.
Originality/value
The authors used the fabric substrate, natural indigo dye and reducing/crosslinker agent of citric acid, all being bio-based, in the fabrication of antibacterial dyed fabric for health care garments.
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Elliott N. Weiss and Gerry Yemen
The airline passenger industry in India was a mess in 2013, but the low-cost carrier IndiGo was making money. This relatively new company had managed to work against the odds and…
Abstract
The airline passenger industry in India was a mess in 2013, but the low-cost carrier IndiGo was making money. This relatively new company had managed to work against the odds and grab market share from longer-established flyers. Still, the weak rupee, depreciated by 15%, was sending a chill wind through the aviation sector, and growth plans would have to include opening new destinations. This meant hiring more employees, opening more ticketing stations, and increasing costs. Could the airline continue its climb, or would it be prudent to prepare for a hard landing?
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Dyeing process is usually to blame negatively for deteriorating the environment. Eco-friendly silk fibers are able to exercising their commercial values well followed by…
Abstract
Purpose
Dyeing process is usually to blame negatively for deteriorating the environment. Eco-friendly silk fibers are able to exercising their commercial values well followed by eco-friendly processing. One of the supporting examples is the process of changing the colors of silk fabrics. This would include the dyeing process used to change the colors of silk fabric. The intention of the study is to reach the goal of creating an eco-friendly finishing process using a local natural plant-based indigo dyeing process that would complement an eco-friendly degumming process. Currently, most dye houses use sodium hydrosulfite (Na2S2O4) and alkali (NaOH) as the substances for providing hydrogen as a reducing agent. Since the sodium hydroxide by-products are acidic, they may damage equipment in the dye houses, generate air pollution in working environment. The other problems associated with the use of sodium hydrosulfite are the cost and instability with low storage.
Design/methodology/approach
This paper is based on continuing improvements to the commercialization of the raw materials via the innovative degumming process elaborated in the author’s previous study: “Degumming of Silk Fibers by CO2 Supercritical Fluid.” The initial study has already proved that it was possible to remove sericin from raw silk fiber by using an organic acid pretreatment and CO2 supercritical fluid over the heavy processes the industry currently deploys. The sericin removed from this innovative and eco-friendly processing of silk fiber will be remained in a clean state, not in the form of waste via the existing technologies in use. Clean sericin, rich in silk protein with high market values, can be a potentially perfect substitute of collagen the medical and cosmetic industries widely use. The continued research is focused on the other by-product coming out from this eco-friendly degumming process the silk fibers post degumming. Dyeing process is usually to blame negatively for deteriorating the environment. Eco-friendly silk fibers are able to exercising their commercial values well followed by eco-friendly processing. One of the supporting examples is the process of changing the colors of silk fabrics. This would include the dyeing process used to change the colors of silk fabric. The intention of the study is to reach the goal of creating an eco-friendly finishing process using a local natural plant-based indigo dyeing process that would complement an eco-friendly degumming process.
Findings
Degumming is an important stage in the silk manufacturing. Due to removing sericin from silk fibers, when subjected the degumming process, these silk fibers acquire the properties, which are of high consumer and commercial values, those include gloss, perfect color, soft handle and texture, elegant drape. Another purpose for the silk fabric degumming is preparing for the next step in processing, such as dyeing or printing. The author has developed a new approach to the degumming process exploiting a supercritical fluid carbon dioxide and found it as a good alternative to the conventional methods that are currently used in industry. Silk fabrics treated by the scCO2 degumming process are characterized by improved dyeing ability or color strength, while this process does not adversely affect the environment. The implications or potential applications of the findings: as it is clearly seen from Table 1, the effectiveness of the degumming process can be improved by at least 38% applying scCO2. Moreover, implementation of the scCO2 silk degumming process into the textile industry may help manufactures to consume less water and energy resources (Elmaaty and Abd El-Aziz, 2017), as well as to obtain pure sericin as a valuable end-product that can be used in the medical and cosmetic industries.
Research limitations/implications
The innovation and novel aspects of research: degumming is an important stage in the silk manufacturing. Due to removing sericin from silk fibers, when subjected the degumming process, these silk fibers acquire the properties, which are of high consumer and commercial values, those include gloss, perfect color, soft handle and texture, elegant drape. Another purpose for the silk fabric degumming is preparing for the next step in processing, such as dyeing or printing. The author has developed a new approach to the degumming process exploiting a supercritical fluid carbon dioxide and found it as a good alternative to the conventional methods that are currently used in industry. Silk fabrics treated by the scCO2 degumming process are characterized by improved dyeing ability or color strength, while this process does not adversely affect the environment.
Practical implications
The author has developed a new approach to the degumming process exploiting a supercritical fluid carbon dioxide and found it as a good alternative to the conventional methods that are currently used in industry. Silk fabrics treated by the scCO2 degumming process are characterized by improved dyeing ability or color strength, while this process does not adversely affect the environment.
Social implications
As it is clearly seen from Table 1, the effectiveness of the degumming process can be improved by at least 38% applying scCO2. Moreover, implementation of the scCO2 silk degumming process into the textile industry may help manufacturers to consume less water and energy resources (Elmaaty and Abd El-Aziz, 2017), as well as to obtain pure sericin as a valuable end-product that can be used in the medical and cosmetic industries.
Originality/value
To make the silk manufacturing more green, the author has developed a technology for obtaining a plant-based indigo dye applying only locally grown agricultural products. The author has found that banana paste and banana peel paste have a sufficiently enough reduction potential for converting the indigo dye into indigo white, which is an important stage in the dyeing processes. The investigation performed showed that both these pastes can serve as a green alternative to sodium hydrosulfite, widely used in industry as a reducing agent. The main result of this study is the demonstration that natural, recyclable and easily biodegradable resources can be exploited to produce the semi-products for the textile industry and the final dyed silk fabrics as well. Summarizing the above, it can be concluded that we have got the results, which show promising alternative green processes for the textile industry in silk treatment (both degumming and dyeing). Their implementation may turn the silk textile production into a sustainable green circle and economically viable manufacturer.
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Kangkang Wang, MengQian Wang, Weiwei Lv, Jiming Yao, Wei Zhang and Xiaoyan Li
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…
Abstract
Purpose
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.
Design/methodology/approach
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.
Findings
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.
Research limitations/implications
The recyclability and biodegradability of the dye remain to be explored.
Practical implications
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.
Social implications
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.
Originality/value
Application of the Fe(II)-DGS-Abal B complex media system in the indirect electrochemical reduction of indigo.
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Weiwei Lv, Zhijie Huangfu, Kangkang Wang, Wei Zhang and Jiming Yao
Indirect electrochemical oxidation and electro-flocculation were combined to degrade indigo wastewater.
Abstract
Purpose
Indirect electrochemical oxidation and electro-flocculation were combined to degrade indigo wastewater.
Design/methodology/approach
The degradation efficiency of indigo wastewater in single-cell and double-cell were investigated. Based on the previous single factor experiments, the oxidative degradation conditions of indigo wastewater in single cell were optimized by response surface methodology (RSM). The decolorization rate, chemical oxygen demand (COD) removal rate, the contents of flocculation precipitation and indigo were measured and analyzed.
Findings
The degradation efficiency in single cell was higher than in double cell. The electrolysis conditions were optimized by RSM and the decolorization rate was 99.01% with COD removal rate of 60.34% and conductivity of 89.75 mS/cm. The amount of flocculated precipitation decreased by 53.33% and the indigo increased by 86.34%. The content of Na and S decreased by 12.13 and 6.49%, respectively. The ratio of Fe3+ to Fe2+ in the solution was 4.62:1, indicating that most of the iron dropped on the electrode sheet was converted to Fe3+.
Research limitations/implications
The one-step electrochemical oxidation and flocculation method with the advantages of simple operation and environmental protection, provided a reference for the actual treatment of dyeing wastewater.
Practical implications
Combining the electrochemical flocculation and oxidation provided an efficient and practical solution for degradation of indigo wastewater.
Originality/value
Combining the advantages of electrochemical oxidation and electroflocculation, the application of electrochemistry in printing and dyeing wastewater treatment technology has been expanded.
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Xiaoyan Li, MengQian Wang, Gang Wu and Jiming Yao
The purpose of this study is to improve the performance of sodium borohydride in reducing indigo at room temperature, the divalent copper ion complex was combined with…
Abstract
Purpose
The purpose of this study is to improve the performance of sodium borohydride in reducing indigo at room temperature, the divalent copper ion complex was combined with electrochemical technology for the reduction of indigo by sodium borohydride.
Design/methodology/approach
According to the K/S value of the dyed cloth sample, find a more suitable ligand for the copper ion in the catholyte. Response surface analysis tests were performed to evaluate the effects of sodium borohydride concentration, sodium hydroxide concentration and copper sulfate pentahydrate concentration on the reduction potential of the dye solution and the K/S value of the dyed fabric samples.
Findings
Sodium gluconate was found to be a more suitable ligand for copper ions in catholyte. The effects of NaOH concentration as well as the interaction of NaBH4 and NaOH on the reduction potential of the catholyte and the K/S value of the dyed fabric samples were extremely significant. The optimal concentrations of NaBH4, NaOH and CuSO4•5H2O were 0.5, 2.5 and 0.65 g/L. In the case of the optimized condition, the absolute value of the reduction potential was 968, and the K/S value was 11.92, which is comparable with that of the conventional reduction process with sodium dithionite.
Originality/value
The divalent copper ion complex combined with electrochemical technology was applied in the process of reducing indigo with NaBH4 at room temperature.
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Wei Zhang, Weiwei Lv, Xiaoyan Li and Jiming Yao
In this study, the oxidative degradation performance of indigo wastewater based on electrochemical systems was explored. The decolourization degrees, removal rate of chemical…
Abstract
Purpose
In this study, the oxidative degradation performance of indigo wastewater based on electrochemical systems was explored. The decolourization degrees, removal rate of chemical oxygen demand and biochemical oxygen demand of the indigo wastewater after degradation were evaluated and optimized treatment conditions being obtained.
Design/methodology/approach
The single factor method was first used to select the electrolyte system and electrode materials. Then the response surface analysis based on Box–Behnken Design was chosen to determine the influence of four independent variables such as FeCl3 concentration, NaCl concentration, decolourization time and voltage on the degradation efficiency.
Findings
On the basis of single factor experiment, the electrode material of stainless steel was selected in the double cell, and the indigo wastewater was electrolyzed with FeCl3 and NaCl electrolytes. The process conditions of electrochemical degradation of indigo wastewater were optimized by response surface analysis: the concentration of FeCl3 and NaCl was of 16 and 9 g/L, respectively, with a decolourization time of 50 min, voltage of 10 V and decolourization percentage of 98.94. The maximum removal rate of chemical oxygen demand reached 75.46 per cent. The highest ratio of B/C was 3.77, which was considered to be more biodegradable.
Research limitations/implications
Dyeing wastewater is bringing out more and more pollution problems to the environment. However, there are some shortcomings in traditional technologies such as adsorption and filtration. As a kind of efficient and clean water treatment technology, electrochemical oxidation has been applied to the treatments of various types of wastewater. The decolourization and degradation of indigo wastewater is taken as an example to provide reference for the treatment of wastewater in actual plants.
Practical implications
The developed method provided a simple and practical solution for efficiently degrading indigo wastewater.
Originality/value
The method for the electrochemical oxidation technology was novel and could find numerous applications in the degradation of printing and dyeing wastewater.
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