Ecological dyeing process

AirDye s process begins with using all synthetic fibers for its material, which can be made from recycled PET bottles. Using dispersed dyes that are applied to a paper carrier, AirDye uses heat to transfer the dyes from the paper to the surface of the textiles, coloring it at the molecular level. All paper used is recycled, and dyes are inert, meaning that they can go back to their original state and be reused. 

Elimination of water consumption Elimination of wastewater discharges Wastewater treatment process eliminated Elimination of drying and dryer effluent Reduction in energy consumption Reduction in air emissions Reduction in dyeing time 

Surfactants and auxiliary chemicals in dyes eliminated Dye utilization is very high with very little residue dye Unused dye can be recaptured 

Approximately 95% of used CO will be recycled Fewer redyes are required 

Color correction is easier compared to aqueous dyeing. 

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In that light, smart dyes fulfil all of the demands, as they enable new technologies and new application fields, while their application methods to textile materials are governed by ecologically friendly processes that have been developed for decades now (Drumond Chequer et al., 2013 Periyasamy, 2012 Pingale, 2004). 

Dyestuffs when exhausted on fibre are fixed only to the extent of 50-90% the unfixed exhausted dye along with additive chemical impurities contaminates the effluent hence, there is a need to ensure that the dyestuff and dye additives that are used in the dyeing process are eco-friendly. Ecological norms for the dye are considered assuming its concentration up to 10% in textiles and 2% dye diluted to 1 2500 in effluent. 

Chequer, F.M.D., Dorta, D.J., Pahna de Oliveira, D., 2011. Azo dyes and their metabohtes does the discharge of the azo dye into water bodies represent human and ecological risks In Hauser, P. (Ed.), Advances in Treating Textile Effluent. InTech, ISBN 978-953-307-704-8. Chequer, E.M.D., Ohveira, G.A.R., Ferraz, E.R.A., Cardoso, J.C., Zanoni, M.V.B., Ohveira, D.P., 2013. Textile Dyes Dyeing Process and Environmental Impact. InTech. 

Dichromate oxidation does tend to give a harsher handle and a less hydrophilic fibre, tending to cause handling problems in subsequent processes such as weaving, and is therefore less suitable for yarn dyeings. The technical merits of dichromate are overshadowed by ecological considerations, however, since chromium compounds in surface waters pose a direct threat to health and are increasingly restricted by water treatment... 

Dioxazine Dyes. The synthetic routes (see below) to almost all dioxazines yield products with a symmetrical structure, resulting in at least two reactive anchors. The highly reactive double-anchor dyes are suitable for both the exhaust and the padding processes. Ecological limits for wastewater are satisfied as a result of a high degree of fixation and low salt requirements in the exhaust process, whereby the latter also has a positive influence on leveling. 

Because of a lack of storage stability in dyeings treated by this method, formaldehyde aftertreatment is mainly confined to dark shades (brown and black). Although the basic, simple process has remained virtually unchanged, its importance has declined sharply for ecological reasons. 

For some typical dyes the C.I. constitution number is given in this book. Any duplication of dyes or application process should be attempted only under the supervision of an experienced chemist who is aware of the latest ecological, toxicological, and safety requirement. This guidance must be constantly observed even if attention is not explicitly drawn to it. 

The most important derivative employed in vat dye manufacture is the reduction product of 2-nitroanthraquinone, namely 2-aminoanthraquinone (61). It was formerly manufactured from the 2-sulfonic acid of anthraquinone, by reaction with ammonia in the presence of oxygen. However, sulfonation of anthraquinone requires mercury and the subsequent animation requires arsenic, making these processes ecologically unattractive. From the early 1970s, processes for direct nitration of anthraquinone at the 2-position, followed by reduction, were introduced, mainly as a result of research in Japan45,46. 

Ecological and Economic Aspects of the Process Change. By use of the pressure permeation technique, wastewater contamination can be decreased considerably and thus the following wastewater treatment simplified. Also, the almost complete removal of salts from dyes marketed in the form of highly concentrated solutions virtually eliminates the necessity of adding auxiliaries for standardization. 

Low-temperature plasma methods were used to modify cotton fibers prior to dyeing. Plasma refers to a partially ionized gas that consists of ions, electrons, and neutral particles (Radetic et al., 2000). Plasma processing is a clean, simple, and multifunctional process that meets today s strict economic and ecological demands. As noted in many previous studies, the main advantages of plasma treattnents are a shortened processing time and the nonexistence of water in the medium (Grzegorz et al., 1983 Oktem et al., 1999, 2000). 

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