The Influence of pH, Temperature and Time on Dyeing of Silk Fabric by Black Bean Anthocyanin-rich Extract as Colorant

Anthocyanins are natural dye substances that provide attractive colors from red to blue. However, large quantities of Anthocyanins have been found in wastewater from soaked black beans, resulting in environmental pollution. The utilization of theses wastewaters would therefore be an effective way of reducing environmental pollution, and the water could be used to dye silk fabric, displaying a more sustainable use of resources. In this paper, the effects of pH, temperature and time for dyeing of silk fabric were investigated. It was found that the optimum dyeing conditions were pH 3 at 60 oC for 60 min to achieve the best colors and the most effective color fastness on silk. Moreover, Anthocyanins were the potential to reduce 80% gram-negative and gram-positive bacteria. These results improved our understanding of dyeing conditions using Anthocyanins in the wastewater from soaked black beans, which plays an important role in reducing pollution, reducing costs and improving the quality of the related dyeing fabric families.