The public awareness and the growing perception of social cognizance about the environment have forced the textile industry to produce environmentally friendly products. For this reason, nowadays many companies and organizations focus on the environmentally friendly way of production. In order to create a sustainable textile, the main change factors have been linked to eco-materials so less and harmless waste, reusing/recycling, lesser usage of energy, water and chemicals and ethical issues in production processes. This article emphasizes the environmental effects of textiles in detail and contributes to cleaner production and sustainability in the textile industry by initiating a discussion on the opportunities for change in textile processes in accordance with the laws.

Problems such as the depletion of natural resources and the increase in environmental pollution brought about by industrialization, the concept of recycling gained great importance. Natural dyes have gained importance again with the increase in environmental awareness. For this purpose, the dyeability of recycled cotton yarns with natural dyes was examined in order to both protect natural resources and reduce the waste water load in dyeing. The paper also discussed a comparison between different ways to mordant cotton with different molecular weight chitosan. Although it was seen by FTIR analysis that cotton fibers were dyed, the presence of chitosan could not be clearly seen. It was explained by the use of low amounts of chitosan. It was observed that the mordanting processes performed with chitosan contributed to the increase in the color strengths, and higher color depths were obtained with the increasing chitosan concentration. Simultaneous mordanting in Curcuma longa dyeing, mordanting before Sandalwood dyeing provided higher color depths than others. The washing fastness of the samples dyed with Curcuma longa revealed the necessity of fastness improvement processes. It was concluded that chitosan mordanting process was effective in terms of sustainable natural dyeing, but it was necessary to improve fastness. Graphical Abstract

Cotton fiber consumption is higher than any other natural fiber due to its superior mechanical and physical properties. In the conventional reactive dyeing process, the dye undergoes hydrolysis due to hydrogen bonding and weak Van der Waals forces, yielding poor washing color fastness. Additionally, the post-dyeing wash-off process consumes significant amounts of water, energy, and time in order to remove the unreacted and hydrolyzed dye. Therefore, reactive dyes are predominantly utilized to color cotton fabrics as the covalent bond formed between dye and fiber results in excellent washing fastness for a wide range of colors, and improved ease of use. To support more efficient, economical, and sustainable reactive dyeing, polymers can be used as effective dye transfer inhibitors (DTIs) in the reactive wash-off process. In this study, poly(vinylpyrrolidone) (PVP) homopolymer and poly(vinylpyrrolidone)-co-poly(vinylimidazole) (PVP-co-PVI) were synthesized at different molecular weights. These polymers were then employed as DTIs to evaluate their performance during the wash-off process for dyed cotton fabrics treated with three reactive dyes (Reactive Red 195, Reactive Blue 221, and Reactive Yellow 145). It is noteworthy to mention that the alternative wash-off procedure involved only three stages, in contrast to the series of washing steps necessary in the conventional method. Evaluation of the DTIs was focused on parameters such as color strength, washing fastness, chemical oxygen demand (COD), as well as energy, water, and time consumption. The findings revealed that while the polymer DTIs generated minor differences in dyed fabric colors in comparison to conventional dyeing, they significantly improved washing fastness. The polymer DTIs studied display excellent potential to provide a much more sustainable dyeing process by saving 90% energy, 40% water, and 50% time versus conventional wash-off processing. The wastewater COD values from the polymer-assisted reactive dye wash-off process were higher for all reactive dyes tested than those from conventional processing. While the higher COD values are attributed to the lower water volumes, this finding highlights the need for further studies. In summary, PVP polymers successfully served as DTIs in the reactive dyeing washing-off process, providing massive water-energy-time efficiency improvements and, subsequently, a more sustainable process for cotton fabric dyeing.