Reactive dye fixation on nylon 6 and nylon 6,6

Fixation of reactive dyes on nylon 6 and nylon 6,6 fibers can be difficult, with nylon 6 being the poorest. Several commercial reactive dyes were tested on both fibers. Most ranges did not achieve good fixation based on the number of colors sufficient for color matching, especially using nylon 6. To understand the reason for this behavior, vinylsulfone reactive dyes with different chromophores were prepared, and their affinity and diffusion were measured and correlated to the fixation on these two fibers. Dyes with high affinity and low diffusion were the ones that showed the highest fixation. The reasons for these relationships are discussed.