Continuous mode of color and functionality construction for cotton by bacterial pigment based on nano-suspension system

As an important industrial crop product, green and efficient processing technology of cotton is the direction that people have been pursuing. As a kind of natural dye with great application prospect, microbial pigment has been widely concerned in the color and functionality construction of textiles. However, at present, almost all reports on the application of microbial pigments in the cotton dyeing are using intermittent processing methods, resulting in long production process, low pigment utilization rate, large resource consumption and other problems. In this research, efficient continuous mode of color and functionality construction for cotton fabric with bacterial pigment based on nano-suspension system was developed, which possessed the advantages of short process, low cost, high pigment utilization rate, and green environmental protection. Under the optimal dyeing condition of dye bath pH 3, rolling pressure 0.75 bar, steaming time 5 min and four-dip-four-nip, dyed cotton possessed soft and uniform color, good color fastness, as well as UV protection property and certain antibacterial and hydrophobic effect. The results of visible light reflection, FTIR and XPS spectra of dyed fabrics proved that the pigments were effectively dyed onto cotton fabrics. Compared with the past dip dyeing, this continuous mode processing with prodigiosins nano-suspension had great advantages of 160% increased utilization of pigment, 80% dyeing process time and 97.8% dye liquid reduction. In addition, nano prodigiosins could not only make cotton fabric appear purplish red, but also yellow color, so that two fabric colors could be achieved with only one single pigment. Because of green environmental protection and natural health property, the dyed fabric was particularly suitable for underwear and baby clothes. The efficient color and functionality construction of cotton fabric with biomass nano pigment provided a new direction for green application of cellulose fibers.