Comparision of biobased and conventional bleaching and dyeing processes for 100% cotton fabrics

In this study, it was aimed to compare the bleaching and dyeing processes performed with conventional chemicals on 100% cotton knitted fabrics, which have a significant place in the textile industry, with alternative processes carried out using biobased chemicals. While traditional chemicals such as hydrogen peroxide and sodium hydroxide widely used in textile production exhibit high efficiency, they also bring along environmental drawbacks such as increased wastewater load, toxicity, and high energy consumption. In parallel with the adoption of sustainable production approaches, biobased chemicals obtained from renewable resources and readily biodegradable in nature have recently started to be evaluated as alternatives in textile processes. Within the scope of this thesis, five different bleaching and three different dyeing processes were performed on the same fabric quality using biobased chemicals supplied by different manufacturers, and comparative tests were conducted. Fabric samples obtained from conventional and biobased processes were subjected to a total of 64 different tests, including whiteness (BERGER), water absorbency, washing, water, perspiration, and light fastness. Additionally, physical performance analyses such as bursting strength, fabric weight (grammage), dimensional stability (shrinkage), skewness, and pilling tests were carried out. The evaluation of the results revealed that bleaching processes performed with biobased chemicals from two manufacturers yielded positive results in terms of whiteness and water absorbency; while the dyeing processes using biobased chemicals were found to be as successful as those carried out with conventional chemicals. Examination of all fastness and physical test results indicated that the processes using biobased chemicals offered values very close to those obtained with traditional chemicals. Particularly, the reduction in water and energy consumption, along with the lower generation of chemical waste, demonstrated that biobased chemicals provide a significant advantage in terms of environmental sustainability. The findings of this study reveal that biobased chemicals can be used as alternatives to conventional chemicals in the textile industry and can contribute to achieving sustainable production goals. However, it was concluded that chemical quantities and process durations must be carefully monitored, and there is a need to establish standards to ensure continuity in production.