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Introduction to Textile Printing
Published in Asim Kumar Roy Choudhury, Principles of Textile Printing, 2023
Most natural dyes are adjective dyes, and do require the application of a mordant (the metal salt) solution to the fibers at some point in the dyeing or printing process. A mordant is an element which aids the chemical reaction that takes place between the dye and the fiber so that the dye is absorbed. Aluminum and iron salts are the most common traditional mordant, while copper, tin and chrome came into use much later. In rural areas where these metal salts were not easily available, plants were also used as mordant, especially those that have a natural ability to extract such minerals from the earth, such as club moss. Most ancient and medieval dyers mordanted yarns and fabrics before dyeing. Alum and iron were used as mordant in Egypt, India and Assyria from early times, as there are many alum deposits in the Mediterranean region. Medieval dyers used alum, copper and iron as mordant, and cream of tartar and common salt were used as to assist in the dyeing process.
Dyes and their application
Published in Michael Hann, Textile Design, 2020
Dyes are classed as either natural or synthetic. As their name implies, the former class are derived from plant, animal or mineral sources, though the clear majority of natural dyes are from plant sources. To ensure that a natural dye fixes to the cloth, a mordant is invariably added; this addition combines with the dye on the cloth to form an insoluble compound. Indigo, woad and walnut husks appear to be the only natural dyes which do not require the addition of a mordant to ensure fastness. Examples of further natural dyes include saffron, logwood chips and madder. Probably the most important step forward in textile dyeing over the past few thousand years was the discovery of the first synthetic dye by William Henry Perkin in the mid-nineteenth century. This first aniline dyestuff (which became known, in Britain at least, as ‘Perkin’s mauve’ or, occasionally, ‘Perkin’s purple’) heralded numerous subsequent developments. Crucial properties of dyestuffs include: the ability to display intense colour; solubility in an aqueous solution (at least during the period of dyeing); substantivity or the ability to be absorbed by the fibres being dyed; fastness or the ability to be retained by these fibres during the anticipated use (Giles, 1971: 27).
List of Chemical Substances
Published in T.S.S. Dikshith, and Safety, 2016
Vanadium is a soft, ductile, silver-gray metal. It has good resistance to corrosion by alkalis, sulfuric and hydrochloric acid, and salt water. Vanadium metal, sheet, strip, foil, bar, wire, and tubing are used in industries. It is used in high-temperature service, in the production of rust-resistant, high-speed tools, and is an important carbide stabilizer in making steels. In fact, most vanadium is used as an additive to improve steels. Vanadium steel is especially strong and hard, with improved resistance to shock. Vanadium pentoxide (V2O5) is perhaps vanadium’s most useful compound. It is used as a mordant—a material that permanently fixes dyes to fabrics. Vanadium pentoxide is used as a catalyst in chemical reactions and in the manufacture of ceramics. Vanadium pentoxide can also be mixed with gallium to form superconductive magnets.
Optimized preparation and dyeing of Pterocarpus santalinus waste extract for enhancing healthy and environmental care performance of wool fabric
Published in The Journal of The Textile Institute, 2023
Dong Yongchun, Liping Wang, Yingwen Yan, Jiayu Gu
However, natural dyes also show some drawbacks, such as low dye uptake, poor fastness, and uneven dyeing on textile fibers (Haji et al., 2020; Sk et al., 2021), especially wool fibers, because of their hydrophobic surface covered by scales. Generally, metallic mordants are required in order to improve the natural dyeing of wool fibers, but which may cause secondary environmental contamination. Besides, other methods including ultrasound energy, microwave heating, plasma treatment as well as enzyme or chitosan finishing have been investigated for enhancing the dyeability of wool fibers with various natural dyes (Haji et al., 2020; Sk et al., 2021). While these processes are often more energy consuming and require the complicated high-cost facilities. On the other hand, the extraction of natural dyes from waste materials is regarded as a cost-effective way of reducing environmental pollution and utilizing natural dyes in recent years. Moreover, some extracts from waste peels of beetroot and red cactus pear (Mansour et al., 2020; Manyim et al., 2022), Ginkgo biloba L. leaves and grape seeds (Gu et al., 2022) were used as natural dyes for the coloring of wool and silk fibers, and gave unique color and high functionalities at a low cost, respectively.
Substitution of metal ion mordant with biomordants: Effect on color and fastness of reseda dyed on wool yarns
Published in The Journal of The Textile Institute, 2022
Razieh Jafari, Kamaladin Gharanjig, Mozhgan Hosseinnezhad
The measurements of washing fastness of dyed wool yarns with Reseda and yellow and black myrobalan (Tables 7 and 8) showed that they approximately have medium to very good resistance towards color-changing against washing treatment. However, rates of staining of dyed samples on cotton are wide-spreading from 2 to 4–5. In addition, all dyed samples demonstrate the grades of good to very good rubbing fastness (rating of 3–4 to 4–5). In summary, according to the results achieved from washing, light, and rubbing fastness, it is found that pre-mordanting of wool yarns with biomordants leads to suitable fastness properties. Comparing the results of Tables 6 to 8 indicates that the key fastness properties of dyed wool yarns in the presence of biomordants are acceptable and in conformity with those of alum. These findings show that both the Yellow and Black myrobalans have the potential to develop the color gamut with reasonable fastness properties on wool yarns in an eco-friendly dyeing method. The fastness properties of dyed samples in the absence of any type of mordant were presented in Table 9. Table 9 shows different ranges of light, wash and rubbing fastness properties. Comparing Tables 6, 7, 8 and 9 indicates that the key fastness properties of dyed wool yarns are improved in some concentrations of natural dye in the presence of mordants. Technically, the use of mordants changes the interactions between the dye and the fiber and modifies the fastness properties due to the improvement of the anchoring properties (Hosseinnezhad, Gharanjig, Razani et al., 2022).
Eco-friendly dyeing of cotton fabric using natural dye from orange peel
Published in The Journal of The Textile Institute, 2022
While, the direct dyeing of natural dyestuffs has poor dyeing reproducibility and low color fastness on cotton fabric (Ding & Freeman, 2017) due to the lack of active groups in the molecule of cotton. As we known, natural dyes are mostly used on silk (Dayioglu et al., 2015; Narayana Swamy et al., 2014; Uddin, 2015; Yin et al., 2018) and wool (Bhattacharya & Shah, 2000; Guesmi et al., 2012; Kaynar & Ucar, 2018; Moiz et al., 2010; Shahid Ul et al., 2018) fabric other than cotton textile. However, mordant dyeing could be used to improve the dye yield of cotton fabric with natural dyes and great attention has been focused on the using of mordant for natural dyes (Cristea & Vilarem, 2006; Davulcu et al., 2014; Ding & Freeman, 2009; Ding & Liu, 2016; Fang et al., 2009; Naveed et al., 2020; Tutak & Korkmaz, 2012). Considering most of the reported mordant is metal, and the dyed textile with metal mordant is hazardous to health of users because of long-term contact with metal salts, and the wastewater is harmful and needs high-cost treatment, exploring new and green mordant to replace the traditional ones is of significant importance.