Improved reactive dye fixation on ramie fiber in liquid ammonia and optimization of fixation parameters using the Taguchi approach

Dyeing in liquid ammonia has the advantage of penetrating the reactive dye molecules inside the fiber structure by modifying the cellulose supramolecular from a crystalline to amorphous form. However, the dye fixation rate of the baking treatment is unsatisfactory (29.45%). In this study, ramie yarn hanks were dyed in liquid ammonia, and cationic fixation auxiliary silicone micro-emulsion was used to fix the dye molecules in the fibers to improve the dye fixation rate and fastness properties. The fixation parameters were optimized using the Taguchi approach. The optimum conditions of the cationic fixation auxiliary mass, fixation time, and water content with four levels on the fixation rate were investigated using an L-16 orthogonal array. The larger-the-better signal-tonoise ratio was applied to maximize the responses of the parameters. The main effect and interaction plot of several factors were analyzed, with results suggesting that the mass of the cationic fixation auxiliary is the most influential parameter for the fixation of the reactive dye (P < 0.05). A fixation rate for the reactive dye of 52.82% +/- 0.5% was observed under the optimal conditions. The color uniformity, wash fastness and rubbing fastness of the dyed sample treated by the cationic fixation auxiliary silicone micro-emulsion were exceptional.