When dyeing nylon fiber, when the pH value of the dyeing solution is relatively high, the dye is rarely dyed; when the pH value of the dyeing solution drops to a certain value, the dye starts to be dyed, and soon reaches saturation. Continue to reduce the pH value of the dyeing night , The dye uptake did not increase significantly; however, when the pH value further dropped to 3, the dye uptake increased sharply, causing super-equivalent adsorption.
Nylon fiber will be hydrolyzed when dyeing under the condition of very low pH value, especially after super-equivalent adsorption occurs, the pH value in the fiber is lower than that in the solution, the hydrolysis speeds up, and more amino groups are produced after hydrolysis. The increased accessibility can absorb more dyes, which makes it easier to produce uneven dyeing. Therefore, according to the actual situation, the pH value can be increased by adjusting the light to reduce the phenomenon of color blur.