Dye-uptake behaviour of nylon-6 filaments and its structural dependence

This article presents results of a study made in two parts on the dye-uptak e behaviour of nylon-6 filaments. In the first part, nylon-6 monofilaments were dry heat-set at temperatures between 80 and 200 degreesC and dyed unde r similar conditions with two dyes, viz. an acid and a disperse dye. In the second part, dry-set and steam-set nylon-6 multifilament yarns were dyed w ith an acid dye. The roles played by the physical structure of the fibre an d chemical affinity between the dye and the fibre have been examined in an effort to explain the differences in the dye uptake results for the two dye s. It was found that the physical structure has a predominant effect in bot h cases; however, in the case of the acid dye, chemical affinity also plays an important role. On the basis of structural studies, some comments are m ade on how structural reorganisation proceeds in nylon-6 fibre on heat-sett ing.