Promising Eco-Efficient Exhaustion Dyeing via Foam Technology: A Full-Factorial Design Optimization Approach

Abstract

This work proposes an innovative approach to the foam dyeing of cotton fabric using direct dyes via the exhaustion technique, which is typically employed in the textile industry. First, foam generation was performed in an industrial dyeing machine and the optimal amount of each foam component was determined, including 3 g/L of the foaming agent sodium dodecyl sulfate (SDS) and 5 g/L of the stabilizer guar gum. Afterward, exhaustion foam dyeing was studied by varying the temperature, dyeing time, sodium sulfate content, and drum rotation until the optimal conditions for this new process were determined. The process was optimized using a full-factorial design approach, and the optimized foam dyeing conditions were as follows: bath temperature: 65 °C, dyeing time: 30 min, sodium sulfate concentration: 20 g/L and drum rotation speed: 40 rpm. The effectiveness of the process was measured through color strength and evaluated for washing, rubbing, and lightfastness. A comparative analysis between foam dyeing and conventional dyeing methods was also conducted. The results revealed that this process saved 55.97% and 52.30% of water and energy consumption costs, respectively. These savings are considered highly significant, offering a valuable opportunity to reduce water and energy costs at an industrial scale. Reducing water usage also directly decreases wastewater generation, thereby minimizing the ecological footprint of textile finishing operations. In addition to reducing wastewater generation, this reduction is expected to lower wastewater treatment costs by approximately 50%. Coupled with lower energy demand, this method supports global efforts to conserve natural resources, reduce pollution, and advance sustainable manufacturing practices.