Ozone utilisation for discharge printing of reactive dyed cotton

Abstract

Environmental pollution is one of the major concerns of the textile finishing sector. The reduction or substitution of the harsh chemicals used during dyeing and printing processes is necessary. In this study, the use of ozone for the discharge printing process was examined in order to substitute the use of reductive agent and caustic soda by ozone gas. The reactive dyed cotton samples were wetted by water and some selected solutions at 25%, 40% and 60% pick up were used and subjected to ozone gas treatment. The gas flow rates were 5 and 10 l/min for 5 and 10 min treatment times, respectively. The results were compared with that of conventional discharge printed samples. Colour discharge (%), colour difference (DE), strength, washing and rubbing fastness and chemical oxygen demand (COD) values were compared and reported. Colour discharge increased at higher gas flow rates and prolonged treatment times. Although ozone printing could not attain the contour sharpness of conventional discharge printing, the addition of selected chemicals affected colour discharge and the contour sharpness. Strength tests did not show a significant decrease when using ozone treatment. Fastness tests results (washing and rubbing) were slightly higher compared with conventional discharge printed samples. COD values were much lower for ozone treatment compared with conventional discharge printing effluent. Consequently, it was demonstrated that ozone may be an environmentally friendly substitute for discharge printing. Coloration Technology Society of Dyers and ColouristsThis article was published online on 16 October 2017. Grammatical and formatting errors were subsequently identified. This notice is included in the online and print versions to indicate that both have been corrected [25 Jan 2018]. The scientific content of the article is unaffected.

Use of Ozone in the Textile Industry

“…However, contour sharpness of conventional discharge printing is much better than that of ozonation. It is not as excellent as contour sharpness of conventional discharge printing [48].…”

Application of Ozone Treatment for the Decolorization of the Reactive-Dyed Fabrics in a Pilot-Scale Process—Optimization through Response Surface Methodology

“…Application of ozone in several domains of textile finishing has been reported. These include reduction clearing of polyester dyed with disperse dyes [5], discharge printing of reactive-dyed cotton fabrics [6], color stripping of reactive dyes from cotton textiles [7], and bleaching of raw cotton textiles [8]. The industrial application of ozone has been limited to denim and garment washing only, and its application to other areas can be a scope of study [9].…”

Atmospheric pressure plasma‐induced decolorisation of cotton knitted fabric dyed with reactive dye

“…Research has shown that indigo‐dyed fabric can be decolorised by plasma treatment with the use of argon and oxygen gases . Moreover, plasma treatment can be used as a treatment method to substitute conventional stonewashing or enzymatic processes to produce a vintage look in fashion textile products, including knitted fabric and denim …”

“…9 Moreover, plasma treatment can be used as a treatment method to substitute conventional stonewashing or enzymatic processes to produce a vintage look in fashion textile products, including knitted fabric and denim. [12][13][14][15] In this study, an industrial scale plasma processing unit was used. 16 Three processing parameters, ie, air concentration, treatment duration and fabric water content, were controlled to achieve the desired decolorisation effect.…”