Savings reactive dyeing

Savings and Cost/Benefit Analysis. The bench scale experiments were successful Tn overcoming major technical problems while demonstrating that dyebath/auxiliary bath reuse is indeed feasible with reactive dyes on cotton-containing fabrics. In addition, a shortened-cycle dyeing procedure coupled with reuse for cotton/polyester blends was shown to further increase energy, mass, and time savings (Table XXX). 

Another approach for removing reactive dye hydrolysates from the fibre and from the wash water (decolourised waste water) is the use of peroxidases (oxidative active enzymes such as Baylase RP). This multipurpose enzymatic rinse process saves time, energy and water but it is restricted mainly to jet applications. The question of the potential toxicity of the resulting aromatic nitro-compounds (cleavage products of the reactive azoic dyes) has to be resolved. 

In reactive dyeing, where ever possible you m try cold dyeing to save energy. Preconditioning method is one such procedure. 

Once the dyeing cycle is complete, the CO is gasified to recover the excess dye. Unburdened, the clean CO cycles back into the dyeing vessel for reuse, a manoeuvre that saves energy, water, and the heavy metals that comprise much of the toxic runoff into our planet s polluted waterways, according to DyeCoo. The process isn t without its limitations, however. DyeCoo is currently only able to dye scoured (or prewashed) polyester fabric, although the company notes that it s working on a version that will dye unscoured fabric, as well as reactive dyes for cellulosie textiles made from plants. 

As shown in Table XII, a broad spectrum of fibers have been successfully dyed in the laboratory with a wide variety of dye classes. A significant process advantage as well as energy savings aspect is the observation that in most cases, the fabrics do not need a back-wash to remove unfixed dyestuffs. The unwashed dyed goods meet all commercial standards for crock and wash fastness. The only exceptions to the no back-wash requirement are in the cases of reactive, sulfur, azoic and pre-metalllzed dyes. 

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