Abstract
The effect of draw ratio on the diffusion of an acid dye Orange II in nylon 6 fiber has been studied in an infinte dyebath at temperatures between 60$^{\circ}$to 9$0^{\circ}C$. The apparent diffusion coefficient in nylon 6 is reduced to about one seventh at pH 4.7, 6$0^{\circ}C$ as the draw ratio increases from 1.0 to 3.4, while one fifth at 9$0^{\circ}C$. Also it is a little reduction in equilibrium adsorption of dye as the fiber is drawn. The apparent activation energy of diffusion, in a temperature range from 60$^{\circ}$to 9$0^{\circ}C$, increases from about 19 to about 25 kcal/mole as the draw ratio increases from 1.0 to 3.4. At pH lower than about 3.0 the adsorption of dye increases abruptly, as the dye anions took place both on charged amino end groups, and amide groups, simultaneously.