Depth Of Shade Research Articles

Pretreatment and dyeability analysis of cotton and novel Bauhinia vahlii fiber

The textile industry is witnessing a paradigm shift towards sustainable materials, prompting the exploration of novel natural fibers as alternatives to synthetic fibers to meet environmental standards and address the growing demand for eco-friendly and sustainable products. Different natural fibers possess varied properties and are suitable for numerous applications in conventional and technical textiles. The coloration of these textile materials is an important aspect of conventional textiles, which starts with the pretreatment of the material. This study introduces a novel blend of cotton and Bauhinia vahlii fiber, a lesser-known natural cellulosic fiber with promising textile properties, and evaluates its pretreatment outcomes and dyeability characteristics. The study employs a systematic approach to pretreat the cotton and Bauhinia vahlii fiber blend (cotton: Bauhinia vahlii fiber 70:30) in a single bath using a conventional combined scouring bleaching process. The pretreatment process is carried out two times with varied sodium hydroxide (NaOH) and hydrogen peroxide (H2O2) concentrations for different processing times at 90 °C to assess the component fibers’ whiteness index, union bleaching balance, and weight loss percentage under diverse pretreatment conditions. Each time, 50% of the chemicals were used and continued for half of the processing time. The dyeability of the treated fibers is analyzed by dyeing the same in a single bath using amron bright red HF2R bifunctional reactive dye in varied shade depths (1%, 3%, and 5%) and fiber blend ratios (cotton: Bauhinia vahlii fiber 100:0, 90:10, 80:20, 70:30, and 0:100) to assess the color strength, union dyeing balance, and fastness properties. The maximum whiteness was achieved with 6 g per liter (gpl) of NaOH and H2O2 and at a processing time of 150 min with a whiteness index of 80.46 and 54.34 of cotton and Bauhinia vahlii fiber, respectively, with a union bleaching balance of 1.48. The dyed fibers’ colorimetric results confirm that Bauhinia vahlii fiber gives higher color strength than cotton fiber, irrespective of shade depth and blend ratio. The union dyeing balance of 1.2 was achieved at 5% shade depth with a 70:30 cotton Bauhinia vahlii fiber blend. This research contributes to the conventional textile field by introducing a sustainable fiber blend that reduces reliance on synthetic fiber and opens new avenues for utilizing Bauhinia vahlii fiber in conventional textile manufacturing.

Performance enhancement of reactive foam dyeing for cotton fabric through different foaming agents and stabilizers

Purpose In the textile dyeing industry, the foam dyeing has been recognized as a significantly sustainable alternative for the cotton fabrics. However, this efficient technology undergoes the many issues related to the foam generation, foam optimization and the required performance of the resultant fabrics. The purpose of this paper is to address these issues through the development and optimization of the novel reactive foam dyeing recipes for the cotton fabrics. Design/methodology/approach The foam dyeing recipes were generated and optimized using the different stabilizers, foaming agents and three primary colors of reactive dyes. The different recipes were applied onto the cotton fabric using laboratory scale foam coating machine. The performance of the foam coated and padded fabrics was evaluated using different criteria including the shade depth, rubbing fastness, air permeability, washing fastness, perspiration fastness, light fastness and tear strength. Then, a complex decision-making approach, namely, analytic hierarchy process (AHP), was applied for the ranking of the key recipes based on the main criteria. Findings The newly optimized foam dyeing recipes were found very competitive with the conventional pad dyeing process with respect to the shade-depth and the other performance properties. The optimization of foaming parameters and addition of stabilizers have advanced the foam dyeing process, which would accelerate the implementation of foam dyeing methods in the textile industry. Furthermore, significant water and energy savings would be achieved as compared to the conventional foam dyeing. AHP model offered a comprehensive and rational way to identify the most important recipes amongst the selected recipes. Originality/value In this research, novel foam dyeing recipes have been developed for the cotton fabrics through the optimization of the different stabilizers, foaming agents and the three primary colors of reactive dyes. Until now, the exiting literature has not reported the combination of these stabilizers with the different foaming agents and three primary reactive dyes for the improvement of sustainable foam cotton dyeing process.

SUSTAINABLE DYEING OF MODIFIED COTTON FABRIC WITH REMAZOL DYES IN THE ABSENCE OF SALT AND ALKALI

This research work investigates the chemical modification of cotton cellulose with a cationizing agent (CHPTAC, 3-chloro-2-hydroxylpropyl trimethyl ammonium chloride), which resulted in the enhanced dye uptake and increased color strength (K/S) on the dyed cotton fabric in the absence costly auxiliaries, such as sodium chloride and sodium hydroxide. The modified and unmodified cotton fabric samples were dyed using the exhaust dyeing method on a high-temperature dyeing machine with several reactive dyes of the Remazol class in different shade depths. The dyed samples were washed, dried and tested for K/S and colorfastness properties (washing, rubbing, and light), using standard test protocols. The results revealed that the color strength and the colorfastness properties of the modified dyed cotton fabric were significantly better than those of unmodified cotton. Thus, this study attempted a sustainable approach in cotton dyeing without using salt and alkali.

Multi-objective optimization for visual, thermal, and cooling energy performance of building envelope design in the composite climate of Jaipur (India)

Climate-responsive passive envelope features such as windows, louvers, and shading have significant impact on a building's energy and economic performance. This paper presents a multi-objective optimization (MOO) approach to enhance energy, visual and thermal performances of a building by considering a wide range of numerous design possibilities. A residential apartment building located in a semi-arid composite climate (Köppen climate classification: Bsh) of Jaipur, India is considered for the analysis. The multi-objective optimization approach involves three steps: firstly, developing a base simulation model using Rhinoceros software, and then performing multi-objective optimization by Octopus plugin, and finally applying multi-criteria decision-making to select the optimal values of thermal conductivity, window-to-wall ratio of south and west façades, solar heat gain coefficient, visual light transmittance, window sill height, louvers depth, distance between slits, slits angle, external shade depth, and shade (slits) count. The optimized results reported a six-fold Useful Daylight Illuminance (UDI) improvement, 72% cooling energy demand reduction, and 34% thermal comfort enhancement from the worst-case scenario. The presented approach can aid designers in selecting optimal envelope features during building design, refurbishment, and renovation or for green field development.

Effect of Microwave Irradiation on Coloring and Mechanical Properties of Direct Dyed Fabric

Microwaves have a very short wavelength which allows them to pass through the small spaces between molecules without being scattered. This allows the microwaves to penetrate the matter and heat it from the inside out, providing uniform heat, and makes microwave technology ideal for applications that require rapid and consistent heating. It has been hypothesized that microwaves may have a positive effect on the shade depth and color fastness of the fabric due to the increased temperature. This research is being done to test this hypothesis and to study the effects of microwaves on the shade depth and color fastness properties of the fabric. Microwave-irradiated fabric dyed before and after dyeing has a greater shade depth and better fastness properties than fabric dyed without irradiation.

Comparative study on dyeing conventional polyester and microfibre polyester with disperse dye and evaluate different dyeing effects

In this study, an attempt was taken to dye conventional and microfibre polyester filaments with disperse dye and evaluate their different dyeing effects in similar dyeing condition. The main attention was given to find out K/S values, color difference and different color fastness properties (light and wash fastness) and also the amount of dyes addition required for microfibre polyester filaments to get the same depth of shade as conventional one’s. There were three different hues (Red, Navy and Green) of 5 different shades (0.5%, 1.5%, 3%, 4% and 6%) were used. The result shows that, microfibre polyester requires higher amount of dyes due to more surface area and greater absorbing capability of it. Almost similar light fastness was found in both conventional and microfibre polyester filaments and lower wash fastness properties of microfibre filaments when compared to those of conventional polyester.

Synthesis of novel pyrazolyl quinolinone derivatives and their physicochemical applications on polyester

Graphical abstract Purpose This study aims to synthesize new disperse dyes based on novel pyrazolyl quinolinone derivatives EQ1 and EQ2 and evaluate their characteristics after dyeing them on a polyester fabric. Design/methodology/approach New dispersed dyes based on pyrazolyl quinolinone derivatives were prepared and confirmed by different analyses, such as infrared spectroscopy, elemental microanalysis and nuclear magnetic resonance spectroscopy. They were dyed on a polyester fabric. The characteristics of dyed polyester were determined by color measurements such as a*, b*, L*, C*, E, Ho, R% and color strength. The electronic structures of EQ1 and EQ2 in gaseous state were investigated using density functional theory/B3LYP/6-311++G (d, p) level of theory. Findings The suitability of the prepared dyestuffs for dyeing on polyester fabrics has been investigated. The study was concerned with comparing the contrasting depth of shade and levelness. The study was concerned mainly with dye uptake and color measurements at two different temperatures. The results showed that the exhaustion values of dyes inside the polyester at 130°C were higher than those obtained at conventional dyeing temperature (100°C). The exhaustion values of EQ2 were greater than those of EQ1 at 130°C with 2.2%, while the brightness of EQ2 was higher than that of EQ1 at the two investigated temperatures. The results of molecular orbital calculations show that the studied compounds are planar. In addition, the ionization potential of EQ1 was lower than that of EQ2. The results of the theoretical study helped in understanding the dyeing behavior of the investigated azo dyes. Originality/value The prepared disperse dyes based on pyrazolyl quinolinone derivatives could be used in textile dyeing of polyester on an industrial scale.

Three-dimensional characteristic chromatogram by online comprehensive two-dimensional liquid chromatography: Application to the identification and differentiation of ginseng from herbal medicines to various Chinese patent medicines

One bottleneck problem in the quality control of traditional Chinese medicine (TCM) is the accurate identification of easily confused herbal medicines from Chinese patent medicine (CPM). Ginseng products derived from the multiple parts (e.g., root/rhizome, leaf, and flower bud) of multiple Panax species (P. ginseng, P. quinquefolius, P. notoginseng, P. japonicus, and P. japonicus var. major) are globally popular; however, their authentication is very challenging. Using online comprehensive two-dimensional liquid chromatography (LC × LC), we propose the concept of a three-dimensional characteristic chromatogram (3D CC) by integrating enhanced LC × LC separation and a contour plot that visualizes the stereoscopic chromatographic peaks and examine its performance in authenticating various ginseng products. Targeted at the resolution of 17 ginsenoside markers, an online LC × LC/UV system with a 56 min analysis time was constructed: a CORTECS UPLC Shield RP 18 column running at 0.1 mL/min for the first-dimensional chromatography and a Poroshell SB-Aq column at 2.0 mL/min in shift gradient mode in the second dimension of separation. In particular, ginsenosides Rg1/Re and Rc/Ra1 were well resolved. According to the presence/absence of stereo peaks consistent with the main ginsenoside markers in the 3D CC and the depth of shade (depending on peak volume), it was feasible to use a single method to identify and distinguish among 12 different ginseng species as the drug materials and the use of ginseng simultaneously from 21 CPMs. Conclusively, a practical solution enabling the accurate identification of easily confused TCMs was provided, covering both the drug materials and the compound preparations.

Design, characterization, theoretical studies, and dyeing properties of new novel diazo salicylaldehyde Schiff base catalyzed with ceric (IV) ammonium nitrate (CAN) as an eco-friendly catalyst

PurposeThe paper aims to the preparation of novel disperse dye based on azo salicylaldehyde derivatives TF-A [2-hydroxy-5-((3-(trifluoromethyl)phenyl)diazenyl)benzaldehyde] and full evaluation of their use as disperse dye TF-ASC [bis 2-hydroxy-5-((3-(trifluoromethyl)phenyl)diazenyl)benzaldehyde Schiff base with 4,4'-methylenedianiline] for dyeing polyester fabric at various conditions.Design/methodology/approachThe dispersed dye was synthesized via Schiff base condensation in the presence of ceric ammonium nitrate cerium ammonium nitrate 10 mmole% as an eco-friendly catalyst at room temperature. The chemical structure of the prepared dye was characterized via elemental analysis, Fourier-transform infrared spectroscopy, 1H- and 13 C-NMR spectroscopic analysis tools. This study thoroughly examined the dyeing of disperse dye TF-ASC on polyester at various conditions. The characteristics of dyed polyester fabric were measured by colour measurements, as well as light, washing, crock fastness and finally, colour strength. The discrete fourier transform (DFT) theoretical studies, including EHOMO, ELUMO and optimized geometrical structure, were assumed and discussed in detail.FindingsThe results showed that the synthesized organic dye TF-ASC was highly functional and appropriate for this kind of dyeing method. The dyeing fabrics obtained from disperse dye TF-ASC, properties possess high colour strength as well as good overall fastness properties. These dyes had a high affinity for polyester fabric, with just a tiny change in dye affinity when the pH was changed, even under alkaline circumstances. The dye levelness and shade depth of the colour results were good, and there were a variety of hues from light brownish yellow to deep brownish yellow. The results obtained from DFT computational studies such as EHOMO, ELUMO, optimized structure, diploe moment µ and electrophilicity index deduced that prepared organic dye TF-ASC is more applicable as a dispersed dye.Originality/valueThis research is significant because it provides a new dye for dyeing polyethylene terephthalate fibres with exceptional brightness and levelness; the method of preparation is a useful pathway due to its being known as a green chemistry method.

Study of the dyeing properties of saffron and ultrafiltrated saffron powders, as colourants for natural and synthetic fibres

AbstractThere is a noticeable growing interest in the use of natural dyes in contemporary textile dyeing, motivated by the requirements imposed, in favour of environmental prosperity. The use of natural dyes reduces significantly both the energy requirements and the environmental impact of the process. In the present work natural and synthetic fibres were dyed with the dyestuff isolated from Crocus sativus L., after aqueous extraction of the dried stigmas of the plant. Additionally, part of the powder was purified by using ultrafiltration technology. The saffron extract and the ultrafiltrated saffron retentate were used to dye cotton, wool, nylon and polyester, in various depths of shade and temperatures. Both saffron and ultrafiltrated saffron successfully dyed not only the natural substrates, but also the synthetic ones, while higher dyeing temperatures produced level dyeing with all substrates used. Ultrafiltrated saffron powder produced brighter and much stronger dyeing to the original saffron powder, due to the elimination of extraction by‐products. Isothermal adsorptions for both colourants were performed on all substrates in order to investigate their adsorption mechanism. It was found that saffron and ultrafiltrated saffron follow a Freundlich‐type adsorption isotherm on cotton, wool and nylon which is a typical mechanism for a planar‐directed dye of big molecular weight. Nernst‐type adsorption was found to occur on polyester which again is typical for the adsorption of disperse dyes on polyester. Thus, saffron can be claimed as a universal dye, able to successfully dye natural and synthetic substrates.

Sustainable process for the pretreatment and dyeing of Eri silk

The green process route for pre-treatment and dyeing of Eri silk is proposed and investigated in this study. The natural plant-based saponins were extracted from Sapindus mukorossi by aaqueous extraction technique. Extracted Saponins showed a high emulsification index (68), low surface tension (41 dyne/cm), mild foaming (200 mm), and a slightly acidic pH, these characteristic properties are considered to be best suited for the processing of silk. The degumming was performed using Sapindus extract liquid with a concentration of 10% (owf) for 60 min at a temperature of 95 °C. The Eri silk degumming produced similar weight loss (4.63%), water absorbency (3 s) and optical properties - whiteness (80.33), yellowness (2.27) and brightness (70.05), as compared to the conventional process. The tensile strength (8.28 kgf)) and elongation (34.29%) was found to be better than the properties of the fabric processed with conventional chemical processing. The dyeing of degummed and bleached Eri silk with natural dyes showed comparable colour depth and uniformity of shade as compared to the conventional chemical processing. The overall fastness performance of dyed Eri silk was in line with the industry standards. Advanced characterization techniques such as FTIR was used for structural analysis of treated Eri silk.

Comparative study of the impacts of fish cage culture on some environmental factors and Macrobenthic communities in offshore farms in the southern Caspian Sea

The aim of this study was to investigate the effects of fish cage culture on Macrobenthic in the southern Caspian Sea. Samples were collected in two offshore farms with four floating polyethylene cages with a production of 60 tons for 5 months in 2015. Sampling was performed of macrobenthos, physicochemical, and sediment in January, March, May, and August at the depths of shade, 50, 100, and 1000 m in three geographical directions (east, west, and south) of the farm. Macrobenthic analysis showed Hypaniola kowalewskii and Streblospio gynobranchiata were predominant, which resulted in an unusual condition due to the effectiveness of the marine farm. There was a linear relationship between environmental factors and macrobenthos communities under the RDA analysis test and the water temperature was the most crucial factor in the density of the dominant species in both fish farm sites. The dominant Macrobenthic species were subjected to environmental conditions in addition to the influence of temperature, salinity, pH, dissolved oxygen, nitrogen, and phosphorus compounds. This situation can be attributed to the hydrological conditions of the studied area; low production of fish, a short period of fish farming, suitable depth of cages established and different water flow directions.

Agrivoltaic System and Modelling Simulation: A Case Study of Soybean (Glycine max L.) in Italy

Agrivoltaic systems (AV) combine agricultural activities with the production of electricity from photovoltaic (PV) panels on the same land area. The concept of AV systems was introduced in 1982 by Goetzberger and Zastrow, but only more recently have the increased environmental concerns and the favorable economic and political frameworks stimulated a growing interest in this technology. A critical issue in the development of AV is the selection of crops that can grow profitably under the micrometeorological conditions generated by AV systems. This experiment studied the effect of four different shade depth treatments (AV1 = 27%, AV2 = 16%, AV3 = 9%, and AV4 = 18%) on the morphology, physiology, and yield of a soybean crop grown under a large-scale AV system. The field results were used to validate the output of a simulation platform that couples the crop model GECROS with a set of algorithms for the estimation and spatialisation of the shading, radiation, and crop-related outputs. Crop height, leaf area index (LAI), and specific leaf area (SLA) all increased under the most shaded AV areas compared to the full light (FL, control) conditions. On average, under an AV system, the grain yield and the number of pods per plant were reduced by 8% and 13%, and in only one area (AV2) was a slight increase in grain yield (+4.4%) observed in comparison to the FL. The normalised root mean square error (nRMSE) value of the predicted grain yield differed from the observed grain values of 12.9% for the FL conditions, 15.7% in AV1, 16.5% in AV2, 6.71% in AV3, and 2.82% in AV4. Although the model simulated the yield satisfactorily, the results of the RMSE revealed that the model tends to underestimate the yield with an increase in shade, particularly for the AV1 and AV2 conditions.

Dyeing of polyester fabrics using novel diazo disperse dyes derived from 1, 4-bis (2-amino-1, 3, 4-thiadiazolyl) benzene

PurposeThis study aims to show the dyeing behaviour of polyester fabrics using four novel heterocyclic disperse dyes.Design/methodology/approachThe four dyes were synthesized based on 5, 5'-(1, 4-phenylene) bis (1, 3, 4-thiadiazol-2-amine) as a diazonium compound. The UV/Vis absorption spectroscopic data of these disperse dyes while dyeing polyester fabrics were investigated. Following this, the dyeing properties of these dyes on polyester fabrics were investigated under acid condition.FindingsThe results showed that increasing the dyeing temperature from 80°C to 100°C led to an increase in dye uptake for all dyes, but further increases of the temperature to 130°C led to higher dye uptake for dye 3 as the dye exhaustion increased by about 50% from 55.9% to 91.4%.Originality/valueThis study is important as it introduces new dyes for the dyeing of polyethylene terephthalate (PET) fibres with colours that range from yellowish orange to bluish yellow and scarlet red and all with excellent brightness, levelness and depth of shade.

Antimicrobial dyeing of cotton from Euclea racemosa root

PurposeThe purpose of this research is to develop an environmentally friendly antimicrobial dyeing of cotton fabric from the root of Euclea racemosa. Textile phytochemical finishing is in high demand worldwide because of its low toxicity, low pollution, ease of availability, renewability, pharmacological effects and non-carcinogenic properties, as well as its multifunctionality, rapid process stages and potential health benefit.Design/methodology/approachThe cotton fabric was dyed with aqueous extracts of Euclea racemosa root dyes. Dyes were extracted for 20 min at pH 7.43 at room and boiling temperatures with material-to-liquor ratios (MLRs) of 1:5, 1:10, 1:15 and 1:20, altering one variable at a time, and the cotton fabric was colored using a post-mordanting procedure at 50°C with an MLR of 1:20. Using a properly cleaned Petri plate, the colored samples were tested in vitro for antibacterial activity. A spectrophotometer was used to assess color strength and shade depth, as well as wash fastness and annual rubbing fastness tests for both wet and dry.FindingsL* = 36.29, a* = 58.56, b* = 32.46 and K/S = 0.51 were the CIELAB values for dye extracted at boiling temperature. L* = 47.14, a* = 42.23, b* = 49.61 and K/S = 0.38 were the CIELAB values for dye extracted at room temperature. The wash and rubbing fastness of the dyed samples were outstanding and the dyed cotton fabrics were found antibacterial against Gram-negative bacteria Escherichia coli.Originality/valueDyes derived from the E. racemosa root could be used to develop a new antibacterial cotton fabric dye.

Exploring Chitosan as an Ecofriendly Agent to Improve Sustainable Dyeing Properties of Cotton Fabric Dyed with (Opuntia Ficus-Indica L) Fruit Peel and Its UV Protection Activity

ABSTRACT This paper explores the use of Chitosan as sustainable agent to improve dyeing properties of cotton fabric dyed with Opuntia ficus-indica L fruit peel and the determination of the amount of anthocyanin pigments by the spectrophotometric method. The results of this study highlights that cotton fabrics treated with chitosan have better depth of shade (K/S = 12) than those untreated fabrics (K/S = 3.7) dyed with Opuntia ficus-indica L fruit peel. We have thoroughly investigated the effects of dye bath pH and temperature on the color properties of the aforementioned fabrics. UV protection of cotton fabrics increased after natural dyeing, and it was further improved after being treated with chitosan. Experimental results show that the fastness properties of dyed cotton fabrics treated with chitosan were improved from average to excellent.

Cationisation of Cotton with Natural Source Based Gelatin for Salt-Free Reactive Dyeing of Cationised Cotton

ABSTRACT Cotton fabric was chemically modified with gelatin, extracted from fleshing waste of collagen by thermal hydrolysis process to increase the dyeing capability of reactive dye. Gelatin imparts new functional groups with fabric and develops Ammonia ion in slightly acid conditions to obtain cationized cotton fabric permit salt and alkali-free reactive dyeing with acceptable shade depth. The imparting of gelatin on the cotton fabric was confirmed by FTIR, UV/VIS absorption, and K/S values. The result shows that they have advantage of high dye utilization and better fastness. Color fastness of treated dyed fabric was equal to the untreated dyed fabric and obtained 4/5 washing fastness, 5 rubbing fastnesses, and 4/5 perspiration fastness. The UV/VIS absorption results show 6.4% improvement in exhaustion and K/S results have 7% improvement in fixation and 9.4% in dye utilization to that of untreated dyeing with salt. Cationized fabric not only increased the exhaustion of the dye but also improved the crease resistance angle at 120° due to the formation of cross-linkage between amide group and the carboxylic acid. To obtain the expected results, cationization was done at alkaline media and the optimum parameter was determined, whereas dyeing conducted at slightly acidic media with optimum parameters.

Printing Effects of Different Natural Colourants on Cotton Fabric

Natural colourants were widely employed in the ancient world to colour cotton garments. With the revolution of synthetic dyes, natural dyes have lost their position in respect of some performance. However, nowadays the demand for sustainable and eco-friendly products is increasing worldwide due to the awareness of ecological balance. The purpose of this study is to utilize natural colourants in printing on cotton fabric. In this regard, the colourants were extracted from myrobalan fruit, pomegranate peel and catechu, which were eventually applied to the fabric by screen printing technique. The print paste was prepared with carboxymethyl cellulose (CMC) as a natural thickener and polyvinyl alcohol (PVA) as a synthetic thickener. The stability of the print paste was studied with respect to time elapse by viscosity measurement. The depth of shade and colour fastness of the printed fabric were measured. K/S value was evaluated with respect to the stability of print paste. The viscosity was changed slightly in both the CMC and PVA thickener with respect to the stability of the print paste. The washing fastness grades for colour staining wash ranged from 4 to 5, rubbing fastness grades of dry rubbing also ranged from 4 to 5, wet rubbing fastness was 3/4 to 4/5 as well as perspiration fastness grades in alkaline, and in acidic it was 3/4 to 5. Thus, myrobalan fruit, pomegranate peel and catechu have shown excellent performance in printing on cotton textiles, which could be an alternative to the synthetic counterpart.

Chemical-Free Dyeing of Cotton With Functional Natural Dye: A Pollution-Free and Cleaner Production Approach

This study is a novel approach toward the development of a chemical-free and sustainable textile dyeing process with minimum environmental risks. Cotton fabrics were cationized with (3-chloro-2-hydroxypropyl) trimethylammonium chloride in four concentrations and subsequently dyed with the black tea extract. Eco-friendly colorant extraction from raw black tea leaves was carried out in aqueous media avoiding the use of hazardous organic solvents. The major coloring components in the black tea extract are polyphenols like theaflavins and thearubigin. Cationized cotton fabrics were dyed in four different shade depths without employing auxiliary chemicals in the dyeing process. For comparison, un-cationized cotton was dyed with the same extract in the same shades. It was observed that un-cationized cotton samples exhibited very low color strength (K/S) values and excellent colorfastness rating. However, the cationized samples showed remarkable enhancement in their color strength with an increase in the concentration of the cationizing agent. Furthermore, colorfastness to washing, rubbing, and perspiration was excellent, but lightfastness was poor. Deep shades (K/S = 8.996) were obtained for cotton sample cationized (20 g/l) and dyed (6%) shades. Thus, the extraction of natural colorants without toxic solvents, economically viable surface modification of cotton, and chemical-free dyeing render the dyeing process cleaner, sustainable, and practicable at an industrial scale. The textile units could easily adopt this approach to regulate a pollution-free dyeing process without modifying their existing infrastructure.

Sustainable Production and Performance Analysis of Cotton Melange Fabrics

ABSTRACT Sustainability issues are gaining momentum in the apparel and textile industries. The use of sustainable raw material, process and recycling are basic approaches for developing the sustainable manufacturing and products of textile. In this study, sustainable fabrics that can fulfil the environmental, economic, and social responsibilities are developed and performances are assessed. Organic cotton fiber, Global Organic Textile Standard (GOTS) approved dyes, and RO treated recycled water are used to manufacture different quality sustainable melange yarns and fabrics. Apart from the novelty in the raw material and manufacturing, Box Behnken experimental design was also incorporated for three factors such as fineness of fiber, noil extraction%, and shade depth%. The use of recycled water and biodegradable raw materials leads to environmental and ecological advantages. In terms of technical performance, fineness, and noil extraction have a significant impact on dimensional, mechanical, and physical properties such as stitch density, areal density, thickness, porosity, bursting strength and abrasion resistance of cotton melange knitted fabrics. Shade depth also considerably affects all the above properties of fabrics except thickness, density, and porosity. Higher areal density, lower thickness, and lower porosity of cotton melange fabric with the high extraction of noil and low value of fiber fineness are found.