Sustainable eco-friendly extraction of yellow natural dye from haar singhar (Nyctanthes arbor-tritis) for bio coloration of cotton fabric

Modeling and optimization of dyeing process of polyamide 6 and woolen fabrics with plum-tree leaves using artificial intelligence

The dyeing process of textile materials is inherently intricate, influenced by a myriad of factors, including dye concentration, dyeing time, pH level, temperature, type of dye, fiber composition, mechanical agitation, salt concentration, mordants, fixatives, water quality, dyeing method, and pre-treatment processes. The intricacy of achieving optimal settings during dyeing poses a significant challenge. In response, this study introduces a novel algorithmic approach that integrates response surface methodology (RSM), artificial neural network (ANN), and genetic algorithm (GA) techniques for the precise fine-tuning of concentration, time, pH, and temperature. The primary focus is on quantifying color strength, represented as K/S, as the response variable in the dyeing process of polyamide 6 and woolen fabric, utilizing plum-tree leaves as a sustainable dye source. Results indicate that ANN (R2 ~ 1) performs much better than RSM (R2 > 0.92). The optimization results, employing ANN-GA integration, indicate that a concentration of 100 wt.%, time of 86.06 min, pH level of 8.28, and a temperature of 100 °C yield a K/S value of 10.21 for polyamide 6 fabric. Similarly, a concentration of 55.85 wt.%, time of 120 min, pH level of 5, and temperature of 100 °C yield a K/S value of 7.65 for woolen fabric. This proposed methodology not only paves the way for sustainable textile dyeing but also facilitates the optimization of diverse dyeing processes for textile materials.

Sugar beet (Beta vulgaris L.) leaves as natural colorant for cotton dyeing using an ecofriendly approach toward industrial progress

In the industrial sector, vegetable residual materials have received attention in the production of bio-colorant for textile dyeing. The current research endeavor is centered on investigating the possibility of using sugar beet leaves as a natural source of dye for the purpose of dyeing cotton fabrics. Different extraction methods were utilized to isolate the bio-colorant present in sugar beet residual material, and the most favorable colorant yield was obtained using a 5% methanolic KOH solution. For optimal dyeing results, the cotton fabric performed dyeing for a duration of 45 min at a temperature of 60 °C, using a salt solution concentration of 6 g/100 mL and 50 mL of the extracted dye solution. Characterization of dye using Fourier transform infrared spectroscopy analysis confirmed the presence of quercetin in the leaf extract. For the creation of a range of color variations, mordants that were chemical in nature, such as tannic acid, iron sulfate, potassium dichromate, and copper sulfate, as well as mordants that were bio-based, such as onion peel, pomegranate peel, henna, golden shower bark, and turmeric, were employed in harmony. In comparison, the utilization of bio-mordants resulted in darker shades that exhibited enhanced color intensity and superior color fastness properties with the value of 4-5 for wash, 4 for wet rubbing, 4-5 for dry rubbing, and 4-5 for light. The findings of this study hold significant value in terms of ecofriendly waste management and contribute to advancements in the industrial sector by utilizing waste residual materials as a natural source of colorants.

Bio-mordants: a review

Due to the increasing pressure on environmentally friendly approaches and sustainable production processes, the textile dyeing industry has focused on natural colorants. Thus, the use of bio-mordants, which are biological materials, has become widespread as an alternative to metal salts, most of which are non-ecological, used in the application processes of natural colorants. In natural dyeing, dyers want to use mordant substances in the dyeing processes in order to both expand the color spectrum and improve the fastness properties. Conventional metal salts used in natural dyeing are made up of metallic ions, which, when released into the environment as wastewater effluent at the end of the dyeing process, cause major damage to the ecosystem. Many researchers have thought about using mordants derived from natural sources to address the environmental problem. This article is a review of the investigation of natural mordants used instead of metallic mordants in the process of coloring various textile materials with natural dyestuff sources. It has been determined that many substances, most of them herbal materials, are used as mordants. In this review, mordants, except for conventional metal salts, are examined under three main groups for a better understanding. These groups are as follows: (i) natural or bio-mordants, (ii) oil mordants, and (iii) new-generation and non-vegetable-based mordants. Here, researchers will find an overview of the most recent developments in green mordants as well as application techniques for a variety of mordants.

Natural colour extraction from horticultural crops, advancements, and applications-a review

The scope for natural colours is increasing because of the awareness of allergic, toxic, and hazardous reactions associated with synthetic dyes. Natural colours are extracted from sources that are naturally available, such as flora, fauna, and minerals. Nature sourced us multiple possibilities of colours with varied shades and hues that are subtle and harmonious when combined. Reasons like the instability of natural colours during industrial processing, seasonal availability of raw materials, fading of colour over time, cost of the benefit, and struggles in attaining sustainability have reduced commercialisation success as synthetic colours. Some plants that yield natural colours are also included in crop rotation practice. Natural dye extraction is a source of employment for the countrified subdivisions of poor developing countries. Indigenous technologies on natural colour extraction are available and have been practiced over the years; due to a lack of documentation and information on colour-yielding plants or products from horticultural crops, and their extraction methods, the use of natural colours is diminishing day by day. Even in recent years, emerging techniques have been adopted in research and development, and the information has not been brought together for the use of industries and allied sectors. Several modern approaches, such as Ultrasonication, microwave, enzymatic, supercritical, pressurised liquid extraction, etc., have proven to give better results in extracting natural colours. Thereby, having instantaneous information will help to go green, be eco-friendly, and effectively utilise all the resources without compromising industrial benefits. Reviewing the availability of natural colours from horticultural crops, classifications, recent trends in their extraction process, and applications in various fields will help achieve the above.

Exploration of natural colourant of (Solanum melongena L.) brinjal plant residues for fabric dyeing: a novel approach towards textile processing

Natural products have become the main focus of mankind due to increasing environmental pollution. The current study was concerned with brinjal plant residues as a source of bio colourant for cotton dyeing. Various media have been employed for the extraction of colourant. Present studies illustrated that excellent colourant yield was obtained in 4% acidified methanol. Cotton fabric was dyed at 50 °C, for 55 min and showed optimised dyeing conditions. Varying chemicals and bio-mordants have been used to achieve elegant shade. Chemical mordanting results revealed that 2% FeSO4as pre-mordant, and 6% TA as post-mordant while in bio- mordanting, 8% of pomegranate peel extract as pre-mordant and 2% pomegranate peel extract as post-mordant indicated a darker shade to mordanted fabrics. Bio-mordanting gave darker shade, and fastness which revealed that bio-mordants have improved the fastness characteristics. FTIR results revealed the confirmation of flavonoids as a colourant for cotton dyeing.

Enhancing wool dyeing with clove bud (Syzygium aromaticum) based natural dye via microwave treatment using a central composite design

This research investigates the viability of using Syzygium aromaticum (clove) as a natural dye for wool yarn through the application of microwave treatment and optimization using central composite design (CCD). As concerns grow over the environmental impact of synthetic dyes and their detrimental disposal in water bodies, the search for eco-friendly alternatives becomes imperative to revolutionize the textile industry. Microwave-assisted extraction of the colorant from clove powder is explored as an efficient and sustainable method, minimizing solvent usage and energy consumption compared to conventional techniques. To enhance colorfastness properties while eliminating the need for toxic mordants, green alternatives such as Al, Fe, and tannic acid, combined with plant phenolics from red sumac, pomegranate rind, and weld, are employed. According to the analysis of CCD, the higher color strength value 18.1653 was achieved using pH = 3, time = 50 min, temperature = 70 °C, and salt concentration = 1.5 g/100 mL. The optimized dyeing conditions also showed a maximum level of colorfastness properties of 5 for light, 5 for wash, 5 for dry rubbing, and 4 for wet rubbing. The findings from Fourier-transform infrared spectroscopy and scanning electron microscopy analyses provide valuable insights into the chemical and morphological changes induced by microwave treatment and dyeing with clove extract. The results affirm the presence of eugenol as a potential active molecule responsible for the captivating color of clove flower buds, validating its suitability as a natural dye source for wool. This study highlights the promising potential of microwave-assisted extraction and plant-based biomolecules as innovative and environmentally friendly approaches in natural dyeing, paving the way for a more sustainable future in the textile industry. Embracing these eco-friendly practices allows the textile sector to reduce its ecological footprint and contribute to a cleaner and greener environment. Further research and implementation of these techniques can foster a more harmonious coexistence with nature, ensuring a healthier ecosystem for all.

Environmentally friendly dyeing of wool and silk fabrics with natural colorant of turnsole (Chrozophora tinctoria L.)

With the increasing demand for environmentally friendly dyes, natural dye has become an attractive option replacing toxic synthetic dyes. Within the framework of this research, the natural dye of Chrozophora tinctoria L. was extracted using the microwave-assisted extraction method under different operating conditions. The influence of different factors influencing the extraction process (such as pH, extraction time, and microwave power) on the extraction efficiency was investigated by means of a multilevel three-factor design. The suggested model has a high coefficient of determination, indicating high predictability and good approximation. Optimal microwave extraction process conditions were obtained at a value of microwave power equal to 650 W, at a pH of 5 during a period of 3 min. Dyed wool and silk fabrics showed very good washing and light fastness properties.

A review of plant-based natural dyes in leather application with a special focus on color fastness characteristics

Dyes/colorants are normally used to improve the aesthetic of consumer products, and leather is one of them. The leather industry plays a significant role in the global economy. However, the leather-making process causes severe environmental pollution. Synthetic dyes are one of the major classes of leather chemicals that are responsible for the enhanced pollution load created by the industry. Over the years, excessive use of synthetic dyes in consumer products created severe environmental pollution and health hazard. Many of these synthetic dyes are carcinogenic, allergic, cause serious health problems for human beings, and have been restricted by regulatory authorities for use in consumer goods. Since ancient days, natural dyes and colorants have been used to make lives colorful. Amid the green movements and environment-friendly products/processes, natural dyes are back to mainstream fashion. Moreover, natural colorants have become a trend due to their eco-friendly nature. The demand for non-toxic and eco-friendly dyes and pigments is increasing. However, the question remains "is natural dyeing sustainable" or "how to make it sustainable." Here, we review the literature reports on natural dye's application in leather in the last two decades. This review article provides a detailed overview and current knowledge base on the various plant-based natural dyes used in leather dyeing, their fastness properties, and the need of the hour in terms of product and process development to make natural dying sustainable. The color fastness characteristics of the dyed leather to light, rub, and perspiration have been critically discussed.

Environmental friendly pollution free bio-dyeing of wool with haar singhar (Coral Jasmine) flower extract

The world's move towards revival of eco-labelled products has created a huge urge to explore new means which are healthier for the global community. Among such means, plant-based bio-pigments for coloration of matrix are gaining worldwide fame, particularly in the textile sector. For the purpose of appraising new source of eco-friendly dyes, using microwave irradiation techniques, Coral Jasmine flowers have been explored for the bio-dyeing of wool. The colorant was extracted in acidic medium owing to nature of fabric, and both stuffs have been exposed to microwave treatment up to 5 min. Bio-coloration of MW irradiated and unirradiated wool was done using MW irradiated and unirradiated extract for observing high yield. Central composite design (CCD) as statistical method was utilized to see the significance of dyeing parameters chosen for mordanting to develop colorfast shades. Different concentrations of sustainable chemicals and bio-mordants as per weight of fabric were employed to introduce new shades with improved colorfastness properties. International standard textile methods determining shade permanency (fastness) have been employed onto selected dyed-mordanted fabrics. Good yield of colorant was observed when MW irradiated wool fabric was dyed at 75 °C for 45 min with extract of 7 pH, having 1.5g/100 mL of salt solution; the promising color yield was observed. As per gray scale ratings observed after ISO standard methods, pine nut as bio-mordant and iron salt as chemical mordant have developed colorfast shades. Conclusively, it can be recommended that methods for the isolation of colorants from new dye yielding plants, MW heating method as suitable clean technology and medicinal-based bio-mordants should be employed for getting permanent gamutes.