When dyeing nylon fibers, when the pH value of the dye solution is relatively high, the dye is rarely applied; When the pH value of the dye solution drops to a certain value, the dye begins to dye and quickly reaches saturation. Continuing to lower the pH value of the dyeing night, there is no significant addition during dyeing; However, when the pH value further decreased to 3, the dye uptake increased sharply again, resulting in over equivalent adsorption.

When nylon fibers are dyed under low pH conditions, they are also subjected to hydrolysis, especially after excessive adsorption. The pH value inside the fiber is lower than that in the solution, and hydrolysis accelerates. After hydrolysis, more amino groups are produced, and the accessibility of the fiber can adsorb more dyes, making it more prone to uneven dyeing. So, according to the actual situation, adjusting the pH value appropriately under light can reduce the phenomenon of discoloration.

Article source: Nylon colored yarn

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