The interest in pH-sensitive textile sensors is growing in the global market. Due to their low-cost production, mechanical stability, flexibility, air-permeability, washability, and reusability, they ...are more suitable than electronic sensor systems. The research tailored the pH-sensitive textile by applying the pH indicator methyl orange to the cotton fabric during conventional dyeing. Adsorption of methyl orange dye to cotton fabric is hindered due to electrostatic repulsive forces between dye anions and negatively charged cotton fibre. To overcome this problem, chemical modification of cotton fabric using a commercial product was performed. The pH sensitivity of the dyed fabric was spectrophotometrically evaluated. In addition, the colour fastness of dyed cotton fabric to washing, light, hot pressing and rubbing was investigated according to valid SIST EN ISO standards. The research results show that the pH-responsive cotton fabric was successfully developed. The chemical modification of cotton fabric is crucial for the increased adsorption of methyl orange dye. The halochromic effect was not only perceived spectrophotometrically but also with the naked eye. The developed halochromic cotton fabric showed poor colour fastness to light and good colour fastness to hot pressing and rubbing, while no significant improvement in colour fastness to washing was observed, even though the fabric was after-treated with a cationic fixing agent. Higher adsorption of the methyl orange dye to the cotton fabric during the dyeing process leads to less wastewater pollution after dyeing with unfixed dye and, thus, a reduction in wastewater treatment costs.
Textile wet processing such as dyeing adds value to the apparel but has the potential to cause significant environmental and human health impacts. The objective of this study is to compare the ...environmental impacts of fabrics made of spun-dyed modal with conventionally dyed modal fabrics (for production in Austria, system "cradle-to-factory gate"). The chosen functional unit is one kilogram of black modal knitted fabric. We assessed energy use, GHG emissions, water use and the impact categories covered by CML 2001 method. We found that the cradle to gate production of spun-dyed modal fabric has 50% lower energy use, 60% lower carbon footprint, and requires only 50% of water and has significantly lower (40–60%) environmental impacts compared to conventionally dyed fabric. Sensitivity analysis with liquor ratios and number of washing cycles does not substantially change the above results. Conventional dyeing in China leads to four-fold higher GHG emissions per kg fabric compared to spin-dyeing in Austria. Finally, we described linkages of sustainable innovation with business value creation. We showed that spin-dyeing can significantly reduce costs for value chain actors, helps reducing the environmental footprint of end products, enhances reputation of brands and retailers, and can contribute to mitigating global problems while catering for the rising demand for clothing fuelled by ever growing world population.
•An LCA was conducted for conventionally dyed and spun-dyed modal fabrics.•Spun-dyed fabric has much lower cradle-to-gate NREU, water use and GHG emissions.•Spun-dyed fabric has 30–50% environmental impacts of conventionally dyed fabric.•Spun-dyed modal fabric creates value such as cost reduction and better reputation.
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