FTIR spectra of purified natural dyes: (a) red sandalwood, (b) breadfruit and (c) manjistha/madder (Rubia) (transmittance values are 25–100%). DSC thermograms of purified natural dyes: (a) babool, (b) breadfruit wood, (c) red sandalwood, (d) sappanwood, (e) marigold and (f) manjistha/madder (Rubia).
Standardization of extraction, mordanting and dyeing process variables: a specific case study
Of the various combinations of double pre-stain systems used, 20% of the total application of harda and natural potassium alum (in a ratio of 50:50) applied sequentially gives better color fastness of all mordant combinations tried. Colorfastness data against the variation of variables in the dyeing process* for dyeing 10% Harda +10% Potassium Alum pre-spilled cotton fabric, then dyed with 4% Madder/Rubia. . detailed study and results of the optimization of conditions of dyeing process variables for tesu as natural dye applied to the mentioned 15% total application of alum + harda pre-spilled cotton are not mentioned here due to its duplication).
Functional finishing to impart/to improve the antibacterial property and UV protection factor (UPF) using natural resource-based finishing agents
Post-treatment with 10% eucalyptus leaf extract on cotton dyed with aqueous extract of 30% tessera, after pre-mordation with 15% alum of pre-modded cotton fabric. Simultaneous dyeing and finishing with 15% harda + alum (50:50) pre-modded cotton fabric with tea tree and eucalyptus leaf extract with citric acid.
Conclusion
MeOH extract of eucalyptus leaves with 1,8-cineole, benzene, nerolidol, limonene, alpha-pinene and beta-pinene, which can participate in cross-linking with cellulose-OH groups in the presence of citric acid and heat, showing a better result to protect the growth of bacteria and also UV protection, while any type of eucalyptus extract contains eucalyptol, alpha-pinene, beta-pinene, alpha-phellandrene, gamma-terpinene, caffeic acid, linalool, geraniol and thymol, which are also strongly responsible for reducing and blocking the growth of bacteria. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/.by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided that the original work is properly cited . . Use of a mixture of red sandalwood wood and other natural dyes for dyeing jute fabrics - studies on the dye.
Physico-chemical studies on the dyeing of jute and cotton fabrics using wood wood extract: Part II - Dyeing kinetics and thermodynamic studies. Comparison of extraction methods for the analysis of natural dyes in historical textiles with high performance liquid. Dyeing jute fabric with tessu extract: Part 1-Effects of various mordants and dyeing process.
The role of natural dyes in the UV protection of fabrics made from vegetable fibers.
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Introduction
- Jack fruits (Artocarpus heterophyllus Lam)
- Turmeric (Curcuma longa)
- Onion (Allium cepa)
- Hina (Lawsonia inermis L)
- Indigo (Indigofera tinctoria)
- Madder or manjistha or Rubia (Rubia tinctorum)
- Tea waste (Camellia sinensis)
- Safflower (Carthamus tinctorius)
- Sappan wood (Caesalpinia sappan)
- Logwood (Haematoxylon compechianum)
- Saffron (Crocus sativus)
- Pomegranate rind (Punica granatum)
- Lac insect (Laccifer Lacca Kerr)
- Cochineal (Dactylopius coccus)
- Mineral sources
In the current scenario, people's environmental awareness about natural products, renewable nature of materials, less environmental damage and durability of the natural products has further revitalized the use of natural dyes in dyeing of textile materials. Printing of textile fabrics with natural dyes is done in India especially in Rajasthan and Madhya Pradesh. Natural dyes have many advantages [2] such as non-toxicity, environmental friendliness, pleasant shade to the eye, and special aroma or freshness of shade [3]; however, natural dyes have some drawbacks: they exhibit poor color reproducibility, poor or inconsistent composition, average wash fastness [4], and less availability in different regions, which are major concerns for its resurgence.
The natural dyes can be classified in different ways, such as based on origin/source type, type of tint, chemical structure [15, 16] and color components. For the vegetable origin of natural dyes, the best source of natural dyes is the various parts of plants and trees. Natural dyes are widely used in the dyeing of most of the natural fibres, e.g.
Here are examples of some important natural dyes [17] which are widely used in the dyeing of textile materials, described below.
Classification of natural dyes 1 By chemical constitution
- Chemistry of natural dyes
- By hue or colour produced
- Application based classification
Dyes belonging to this class have anthraquinone structure and are obtained from plant and insect. Depending on the presence of a specific group in the dye structure, the chemistry of the dyes can be explained in terms of their chromophoric groups. After the neutralization of extracted solution, it can be used in the dyeing of wool, silk and cotton.
Lawsone forms a 1:2 complex with Fe(II) and Mn(II) and is useful for dyeing wool and silk fibres. Hina can be used for dyeing cotton, polyester, polyamide and cellulose triacetate, as the structure of dye molecules is similar to disperse dyes [22-24]. The classification of natural dyes is also carried out according to the shade of the color.
Yellow: There are 28 yellow natural dyes used in dyeing wool, silk and cotton.
Extraction of natural dyes
- Aqueous extraction
- Acid and alkali extraction
- Ultrasonic microwave extraction
- By fermentation
- Solvent extraction
Solubility of natural indigo is done with the help of sodium hydrosulphite and sodium hydroxide. After digestion, it is applied to cellulose fibers and after dyeing, color development is done by oxidation with hydrogen peroxide. Direct dyes: Natural dyes which are soluble in water and have a long and planar molecular structure and the presence of conjugated bonds (single and double bonds) can be applied by the direct dyeing method.
The treatment is done at lower temperature and less time compared to aqueous extraction. Ultrasonic and microwave waves are sent into aqueous solution of natural dye, speeding up the extraction process. In the presence of bio-enzymes, the fermentation of natural color-carrying substances becomes faster, and the extraction of natural colorants takes place.
Organic solvents such as acetone, petroleum, ether, chloroform and ethanol are used in the extraction of natural dyes.
Characterisation of natural dyes
- UV-visible spectroscopy
- Chromatographic technique
The extraction of lac dye from lac insect and red dye from safflower is also done with this method. Cellulose, amylose and pectinase are applied in the natural dye extraction from the bark, stem and roots. The value of the wavelength of the maximum absorption for a specific dye depends on the chemical composition of the dye molecules which is variable and depends on the growth environment of a particular natural dye.
The characterization of a particular dye is useful in determining the hue of the color. Balakina [48] quantitatively and qualitatively analyzed red dyes such as alizarin, purpurin and carminic acid by high performance liquid chromatography. Derivative spectroscopy and HPLC were used to analyze annatto dye; sample preparation involved extraction with acetone in the presence of HCl and removal of water by evaporation with ethanol.
The residue was dissolved in a mixture of chloroform and acetic acid for derivative spectroscopy or with acetone for HPLC.
Theory of dyeing
Natural dyes have a smaller molecular size and do not have a conjugated linear structure [57].
Application of natural dyes
- Conventional method of dyeing
- Dyeing of cotton fabric with natural dyes
- Dyeing of protein fibres
- Dyeing of synthetic fibres
- Fixation of natural dyes
- Mordanting process
In the state of Maharashtra, Gujrat and Rajasthan [59] the people follow the conventional method of dyeing cotton fabric with natural dyes which can be explained with the following process sequences. The wool and silk can be dyed with natural dyes by means of pre-dyeing or post-dyeing. Different synthetic fibers such as nylon, polyester and acrylic can be dyed with natural dyes such as onion peel extract, baboon bark extract and hina.
The fixation of natural dyes on textile materials can be done with the help of mordants. Some metal salts are toxic in nature, but even then they are applied in the fixation of natural dyes. It is a two-bath process in which the first bath is used for smearing material and in the second bath is dyed with natural dyes.
Fiber and yarn dyeing can also be done with natural dyes, similar to applying synthetic dyes.
Fastness properties of natural dyes
- Light fastness
- Washing fastness
- Rubbing fastness
It is necessary to investigate some natural post-treatments to improve the light and wash fastness. The poor light fastness is due to chromophoric change in dye structure after absorption of light. He studied the use of tannin-related post-treatments on mordable dyes to be used in cotton dyeing to improve light and wash fastness, and his findings were useful in improving the true properties of natural dyed fabrics.
This shows the dependence of the durability properties of natural dyes on the type of mortants. To improve the light stability of natural dyes, Lee [63] praised the UV absorber on protein fibers. A critical review of the fading process of natural dyes to reproduce the original fabric color after fading.
29] studied the effect of the alkalinity of the washing solution in the washing of natural dyes, dyed fabrics.
Advantages of natural dyes 1 UV-protective fabrics
- Insect proof
The adhesion of dye to fibers is very poor, and as a result dyes are not very fast with detergent solutions. The alkaline pH of the detergent solution changes the color value in terms of hue and value. 8, 58] reported that jackfruit wood, manjistha, red sandalwood, babool and marigold have good rub resistance on jute and cotton fabric.
Summary and conclusions
- Sources of different natural dyes and their characterization
- Application of natural dyes on different textiles
- Natural dyes cum natural antimicrobial finishing agents
- Natural dyes cum natural UV protective finishing agents
A comprehensive review on the application of natural dyes in textiles and previous research findings are discussed in this chapter. However, due to the advent of synthetic dyes and their good fastness properties compared to natural dyes, the use of natural dyes has suffered drastically. Natural dyes are extracted and isolated, and the resulting colored substance is used to dye wool fibers.
The advantages of natural dyes over synthetic dyes are numerous [57], as they are environmentally friendly, safe for contact with the body and are coordinated, as reported by Brian [58]. Many scientists have also suggested and reported the medicinal and antibacterial importance of natural dyes [59, 60]. Most natural dyes are proven to be non-toxic and environmentally friendly, although there are some exceptions.
The natural dyes are the dyes extracted from the vegetable matter, minerals or insects [62]. The application of natural dyes such as turmeric, madder, catechu, Indian rhubarb, henna, and tea and pomegranate peel to man-made fiber nylon is over. High performance liquid chromatography (HPLC) has also been used by various workers to identify synthetic as well as natural dyes.
Conclusions
Eco-friendly dyeing of wool with natural dye from welding as a partner with synthetic dye. Natural color of wool and hair with indigo carmine (C.I. Natural Blue 2), a blue dye based on renewable resources. Dyeing ecru denim with onion extract as a natural dye using potassium alum in combination with Harda and tartaric acid.
Dyeing Jute Fabric with Tesu Extract: Part 1—Effects of Different Mordants and Variables in the Dyeing Process. Dyeing of jute and cotton fabrics with jackfruit wood extract: Part I - Effects of stain and dyeing process variables on color yield and color fastness. Physico-chemical studies on the dyeing of jute textiles with natural dyes extracted from red sandalwood.
Use of a mixture of red sandal wood and other natural dyes for dyeing jute fabrics - dye compatibility studies.
