Single-step Single Bath Dyeing and Finishing of Nylon with Disperse Dye and Chitosan by Using Decamethylcyclopentasiloxane Solvent as Dyeing Media

This investigation was conducted to reduce the water and raw material consumption, and shorten the processing time by carrying out the dyeing and finishing process in a single-step and a single bath by using decamethylcyclopentasiloxane (D5) solvent as dyeing media. The nylon fabric was dyed with disperse dye and finished with chitosan in D5 solvent in a single-step. To improve the durability of the chitosan finish, the chitosan was ball milled into nanoparticles. Furthermore, nylon fabric was dyed with a high dye concentration, 3.2 %(o.w.f.), for assessing the feasibility of a single-step dyeing process for darker shades. Antibacterial activity, color strength, and SEM analysis of treated fabrics reveal that nylon fabric can be dyed and finished in a single step and single bath in D5 solvent. As compared to conventional aqueous dyeing, the single-step dyeing and finishing methodology yielded 53 % higher color strength. The 100 % reduction in bacteria colony forming units (CFU) was achieved with a 1 % concentration of milled chitosan. The fabric treated with milled chitosan sustained its antimicrobial activity even after 5 washes.