Eco-friendly dyeing of fabric using banana sap mordant and mahogany sawdust extract natural dye

Interest in natural hair dyes is continuously growing as these are green alternatives to synthetic dyes. A single natural dye may not be the right color for many people. In this study three different mixtures of famous natural hair dye Lawsonia inermis with different other plants were evaluated for their new shades and dyeing properties. Color strengths of naturally dyed hair were also compared with synthetic dyes and individual plants as well. Mordanting was carried out using some metals and a natural mordant which increased the color strength and wash durability of natural dyes. Colorimetric properties of dyed hair were obtained in terms of CIEL*a*b* and K/S values. Maximum value of K/S was obtained by postmordanting of dyed hair with ferrous sulfate. Yellowish brown to brown shades were obtained by natural dye combinations which were changed to black after application of mordants. The color strength was acceptable even after twenty washes. Overall color strength values of naturally dyed hair with plant mixtures were much higher than individual plants extract. However, these color strength values are very comparable with the synthetic hair dyes proving natural dye combinations be successful candidates for natural hair dyeing with good performance and properties.

Coloring materials for fabric painting can be produced from natural dyes and synthetic dyes. Natural and synthetic dyes have their respective advantages and disadvantages. The combination of the two colors will give the impression of a brighter color, and slightly reduce environmental pollution. The objectives of this research are: 1) Knowing the processing of synthetic and natural dyes for fabric painting; 2) Knowing the results of applying synthetic and natural dyes to fabric painting. The method used in this research is the research and development approach model Research and Development (R&D) and data analysis. Trials in this study were carried out with dye using 4 types of cloth with the help of a validator as an assessor of the coloring results. The results of this study indicate that synthetic dyes are lighter than natural dyes. Meanwhile, the colors produced from natural dyes tend to be darker. In painting this cloth, the writer needs a combination of dark and light colors. Therefore, the use of synthetic and natural dyes requires mixing of colors. The fading test conducted by the author for the color absorption of diamond crape on the fabric is very good. Thus it can be concluded that the use of natural and synthetic dyes can be applied to fabric painting by conducting trials first to get the right color.

PurposeThis paper aims to select a type of mordant from aluminium salts, namely, aluminium sulphate, aluminium nitrate and polyaluminium chloride (PAC) with the lowest potential for contamination so that their use will minimise pollution from natural dye waste. It also aims to determine the pollution value of natural dye immersion waste from jackfruit wood extract, secang wood, mangsi fruit and several synthetic dyes, to identify potential environmental pollution.Design/methodology/approachDyeing with natural dyes was performed by exhaust at room temperature by the pre-mordant method, while with synthetic dyes it was performed by exhaust according to the dyeing procedure (reactive, vat and naphthol). The groundwater, mordant solutions, natural dye extract and the waste-water from the natural and synthetic dyes were then tested to determine their biological oxygen demand (BOD5), chemical oxygen demand (COD), total suspended solids (TSS), pH, Al and heavy metal contents such as chromium (Cr), copper (Cu), cadmium (Cd), nickel (Ni), cobalt (Co) and lead (Pb).FindingsAluminium sulphate had the lowest pollution load while PAC had the highest, as aluminium sulphate had a higher BOD5/COD ratio (0.62–0.67) than aluminium nitrate (0.56–0.64) or PAC (0.44–0.54). The dyeing waste from the three natural dyes contained an acidic pH of 3.5–4.2, Al of 75.280–621.34 mg/L, Cr of 0.154–0.215 mg/L and Cu of 0.035–0.072 mg/L. The values of TSS, COD and BOD5 are higher than the quality standards of the waste but are environmentally friendly because the ratio of the BOD5/COD values from the waste ranges from 0.44–0.67.Research limitations/implicationsThe findings indicate that as a mordant, aluminium sulphate results in lower pollution loads than aluminium nitrate and PAC. However, all three mordants contain Cr and Cu, albeit in negligible concentrations. Therefore, it is recommended that future studies strive to identify a mordant that has lower pollution loads and does not contain metals but can increase dyeing results to satisfy consumer requirements. It is the hope that, with the discovery of a new mordant, natural dyes will be the solution for the heavy metal pollution caused by synthetic dyes.Practical implicationsThe use of environmentally-friendly mordants and natural dyes in the Indonesian textile and batik industry will give rise to superior quality eco-textile and eco-batik products. Such environmentally-friendly and high-quality products will not only increase competition and consumer interest but increase product sales as well which will, in turn, increase incomes and the economy. Additionally, an increase in the use of natural dyes by the textile and batik industry will serve as additional income to the communities and farmers from which the raw materials for the natural dyes are sourced thereby creating jobs and increasing welfare.Social implicationsAs environmentally-friendly mordants and natural dyes replace the hazardous and toxic materials currently used in the textile and batik industry, it guarantees the health and safety of its consumers and workers. Furthermore, as the waste-water produced is biodegradable, it reduces river and groundwater pollution. It is, therefore, expected that this information will not only lead to a shift in attitude within the textile and batik industries but the adoption of environmentally-friendly materials, for the sake of the environment, as well as the development of eco-textile and eco-batik products.Originality/valueAluminium sulphate is a mordant type of aluminium salt with a lower potential for contamination than aluminium nitrate and PAC. However, PAC has been discovered to be a mordant for natural dyes, as has the fruit of the mangsi shrub, which has recently been discovered as a naturally occurring blue dye.

It is well known that cotton fibres can be dyed through the formation of coordinate bonds involving cellulose chains, mordants such as alum, and natural dyes such as alizarin. Similarly, synthetic dyes known as mordant acid dyes can be used to dye wool fibres. Unlike mordant dyes on wool, the fastnesses of natural dyes on cotton are often low. Although concerns surrounding textile sustainability have sparked renewed interest in the use of natural dyes, extensive replacement of synthetic dyes with natural dyes is neither practical nor fundamentally possible. However, similarities in dyeing methods using mordant and natural dyes raise the possibility of using mordant dyes as alternatives to natural dyes in the dyeing of cotton. Further, the potential for combining suitable dyes from these two classes to expand the colour gamut currently available from natural dyes on cotton seem worthy of exploration. The results of this study indicate that shades comparable with those produced by natural dyes can be obtained on cotton using select mordant dyes following Fe2+ and Al3+ pretreatments. The best results were obtained using a two‐step/two‐bath process and dyes such as CI Mordant Blue 13 and CI Mordant Orange 6. In evaluations of mordant and natural dye combinations using the two mordant dyes logwood and Osage orange as prototypes, interesting fabric shades were obtained. However, the fastness properties of these dyes must be improved in order to produce commercially viable dyeings.

The main goal of the study is to produce eco-friendly furniture dyes by using bio-colorants and to determine the color stability of these dyes in outdoor conditions. In this regard, dye extracts obtained from red beet (Beta vulgaris), safflower (Carthamus tinctorius L.), and purple cabbage (Brassica oleracea), as a bio-colorant source, were applied to MDF test panels by mixing with water-based synthetic lacquer coatings. Also, three different synthetic dyes were applied to MDF test panels in order to compare the results with eco-friendly natural dyes. Natural dyes were mixed with metal and natural mordants such as iron sulfate, aluminum sulfate and vinegar. Lacquer coated test panels, coated with natural and synthetic dyes, were exposed to outdoor conditions for 50 days in Denizli/Turkey in order to assess the change in color. As a result, the maximum color stability occurred in the test panels lacquer coated with synthetic black dye, while the minimum color stability occurred in the test panels lacquer coated with synthetic light blue dye. It was determined that the thickness of the color coating layer applied to test panels increases color stability. It was also observed that the color stability performance of natural dyes is as good as that of synthetic dyes.

Using more sustainable materials and products, the textile sector has been able to contribute to the circular economy. Moreover, the textile industry is witnessing a paradigm shift for more sustainable production methods due to enhanced environmental restrictions and rising consumer preferences for eco-friendly textile products by using the natural fibres and natural dyes. Petroleum-derived synthetic colourants are being used extensively in the textile industry due to their wide colour range, fastness, and affordability which resulted utilisation of significant amounts of fossil fuels and resources. In result, synthetic colours contribute to pollution problems and some of them are even hazardous. Industries are actively seeking alternate approaches to mitigate the detrimental impact of manufactured colourants and chemicals on the environment and human health. This article comprehensively reviews the significant developments in the dyeing of hemp with natural dyes. Several plants like inula, agro-food industry leftovers (chestnut and onion), and logwood and madder have been used for dyeing hemp textiles and examined colour strength and the UV protection characteristics which is the growing demand of "eco-friendly" market. Further, Various natural dye extracts such as calendula (Calendula Officialis), common madder (Rubia Tinctorum L.), pomegranate peel extracts (Punica granatum) and dried Buddleja officinalis flower extracts have been utilised for dyeing the hemp fabrics with various metallic, natural mordants with different mordanting condition and assessed the various parameters like colour strength (K/S), colour fastness properties. The dyed fabrics from pomegranate peel extracts have shown significant antibacterial activity and good colour fastness against laundering, water, sea water, and perspiration. Efforts are underway to utilise natural dyes in order to achieve comparable outcomes to those achieved with synthetic dyes. Understanding the various natural materials for dyeing the Hemp and their characteristics provides a new insight for the dyeing industry and inspiring to carry out the research in similar natural materials.

The extraction of natural dye using an aqueous method is a concept of green chemistry to avoid environmental pollution and toxicity. The present study was performed to improve the color strength and fastness properties of the fabrics by using natural dye and banana pseudo stem sap as a natural mordant. The natural dye was extracted from marigold flowers (Tagetes erecta) and optimized for dyeing of cotton and silk fabrics. The extraction of the dye was done in an aqueous solution without using any solvents. The optimum results were obtained when the fabric was dyed at 80°C for 60 min by keeping the mass to liquid ratio 1:40 at pH-7 (1.19). The color strength and CIELab (L*, a*, and b*) color parameters were also investigated. The effect of banana pseudo stem saps as a natural mordant on the color strength and fastness properties of the cotton and silk fabrics were evaluated and compared. The cotton fabrics were further characterized by FTIR spectroscopy and Scanning electron microscopy (SEM) to assess the physical and chemical changes after dyeing and mordanting.

Upcycling sawdust into colorant: Ecofriendly natural dyeing of fabrics with ultrasound assisted dye extract of Pterocarpus indicus Willd.

Fast foods and variety food items are populating among the food lovers. To improve the appearance of the food product in surviving gigantic competitive environment synthetic or natural food dyes are added to food items and beverages. Although regulatory bodies permit addition of natural colorants due to its safe and nontoxic nature in food, synthetic dyes are stringently controlled in all food products due to their toxicity by regulatory bodies. Artificial colors are need certification from the regulatory bodies for human consumption. To analyze food dyes in different food samples many analytical techniques are available like high pressure liquid chromatography (HPLC), thin layer chromatography (TLC), spectroscopic and gas chromatographic methods. However all these reported methods analyzed only synthetic dyes or natural dyes. Not a single method has analyzed both synthetic and natural dyes in a single run. In this study a robust ultra-performance liquid chromatographic method for simultaneous identification of 6 synthetic dyes (Tartrazine, Indigo carmine, Briliant blue, Fast green, malachite green, sunset yellow) and one natural dye (Na-Cu-Chlorophyllin) was developed using acquitic UPLC system equipped with Mass detector and acquity UPLC HSS T3 column (1.8 μm, 2.1 × 50 mm, 100Å). All the dyes were separated and their masses were determined through fragments’ masses analyses.

Textile coloration is a complex process involving the interaction of dye molecules with fibers in a dye bath. Synthetic dyes pose environmental hazards, leading to increased interest in natural dyes sourced from plants, animals, and minerals. However, natural dyes often require mordants for application to textiles. Despite their eco‐friendliness, natural dyes can exhibit poor wash fastness on fabrics, necessitating further research to enhance their performance. This study investigates the use of mahogany sawdust extract as a natural dye for cotton coloration, focusing on the enhancement of fastness properties through metallic mordants and associated environmental risks. Mahogany sawdust, rich in flavonoids and tannins, shows promise as a sustainable alternative to synthetic dyes. The dyeing process involves the extraction of natural dyes from sawmill bio‐waste and subsequent application onto cotton fabrics using various metallic mordants. Evaluation of colorfastness properties, color strength, color coordinates, tensile strength, FTIR, and SEM analysis provides insights into the dye‐fiber interactions and fabric properties. Environmental risk assessment considers metal exhaustion onto fabric surfaces, residual metal concentrations in mordant baths, and metal content in dyeing wastewater. Overall, this study contributes to the development of sustainable dyeing processes and highlights the importance of environmental considerations in textile coloration.Highlights Mahogany sawdust extract: potential natural dye for sustainable cotton coloration. Metallic mordants enhance colorfastness and fabric durability in dyeing processes. Comprehensive analysis reveals the intricate dynamics of dye‐fiber interactions. Environmental risk evaluation guides sustainable textile manufacturing practices. Research paves the way for greener, more sustainable textile industry practices globally.

Photosensitizers have an important role in increasing the ability to capture light. One of the main components of dye-sensitized solar cells (DSSCs) is dye. In general, DSSC fabrication uses synthetic dyes such as N719 and DN-F01. However, synthetic dyes have the potential to have negative impacts on human health and the environment. In this research, DSSC fabrication was carried out using natural dyes and synthetic dyes at large sizes (one cell with an active area of 18 cm2 and two cells with an active area of 15 cm2). The natural dyes used are anthocyanin from red dragon fruit (dragon fruit dyes) and curcumin from turmeric powder (turmeric dyes). Natural and synthetic dyes were characterized using UV-Vis and FTIR spectroscopy. Meanwhile, DSSC performance was characterized by the I-V meter. The best electrical performance for natural dyes was obtained with an active area of 15 cm2 which was sensitized using turmeric dyes with a performance of Eff = 0.020%, Jsc = 0.142 mA.cm-2, Voc = 0.372 V, and FF = 0.461. Furthermore, the best electrical performance for synthetic dyes was obtained with an active area of 15 cm2 which was sensitized using N719 with a performance of Eff = 0.264%, Jsc = 1.303 mA.cm-2, Voc = 0.510 V, and FF = 0.398. Based on these results, natural dyes are less effective than synthetic dyes, but natural dyes are more environmentally friendly and cheap.

Veneer dyeing is typically carried out to achieve a desired colour in the veneer while allowing the grain to show through or to reduce colour variations and achieve a more uniform appearance. In this study, the influence of dyeing temperature, dyeing time and the addition of mordants on the colour and lightfastness of oak and maple veneers was investigated. Wood veneers were dyed using two synthetic dyes (reactive and acid) and two natural dyes (madder and logwood). The study analysed colour change, colour strength and grain contrast after dyeing, as well as colour stability and depth of colour change after artificial exposure. The results showed that temperature, time, and mordant addition had a greater impact on the colour change and colour strength of veneers dyed with natural dyes compared to those dyed with synthetic dyes. On most veneers, higher grain contrast was achieved at lower dyeing temperature and shorter dyeing time. Additionally, mordants reduced the grain contrast of reactive and natural dyes. Furthermore, veneers dyed with natural dyes exhibited less colour change during artificial exposure compared to those dyed with synthetic dyes. Among the tested dyes, the best lightfastness for oak and maple veneers was achieved with madder natural dye.

atural dyes are known for their added benefits over synthetic dyes in terms of health and ecology. They are considered to present a limited range of shades, which limits their use in high-end value-added products. Thus, to explore natural dyes on large scales, it is essential to generate a wide range of shades like synthetic dyes. Therefore, it is important to explore the secondary shades of natural dyes especially those which can act as primary colors in the recipe (red, yellow and blue). In the present work, three natural dyes, namely indigo, pomegranate peels and kumkum were used to dye the polyester fabric. Along with color strength at different dye concentrations, functional properties such as antioxidant, antibacterial, and UV protection were also evaluated. The dyed polyester showed good color values (K/S>1.7) and also displayed satisfactory color fastness to light, washing and rubbing. The polyester fabric dyed with pomegranate and kumkum in self-shades displayed a variety of functional properties including a bacterial reduction of more than 90%, radical scavenging activity of greater than 90% and also displayed excellent UPF values (UPF > 270). Indigo-dyed samples displayed antibacterial activity and UV-protection; however, their antioxidant activity was poor. The secondary shades of these dyes were produced on polyester fabric.

In today’s world, with people’s increasing tendencies toward environmental consciousness and healthy living, organic products raise more and more interest in the textile sector. In textile dyeing operations, many synthetic dyes and auxiliary chemicals are currently in use. Production steps of these synthetic chemicals and discharging chemicals to the aquatic media after utilizing in textile dyeing operations can have toxic and pollutant effects on human and environmental health. Classical natural dyeing techniques are quite expensive, and there are no industrial application processes for the classical natural dyeing techniques. After industrial treatments, plant products such as Rosa damascena flowers produce considerable amounts of wastes that contain natural dyes. This industrial waste from rose flowers could serve as a source for the extraction of natural dyes. In this study, we investigated the industrial waste rose flowers used for dyeing of wool yarn and an industrial process designed for using herbal pulps as natural dyes. This industrial process using rose waste and wool yarn was on an industrial scale. Mordants were selected from non-toxic metal salts and some organic acids. Colour strength and fastness properties (washing, rubbing and light properties) of the yarn were tested. Test results of the dyeing demonstrated that herbal pulps have the potential to be used as a source for natural dyestuff extraction at low cost and show additional possibilities for industrial application. The Pb2+ adsorption capacity of the ultimate rose pulp was investigated, and the results show that the rose pulp that remains after dye extraction can be used as an adsorbent.

Rapid separation and determination of synthetic and natural yellow dyes in food and drinks using mini-column packed with polyamine-modified silica.