Instructions for Using Sodium Acetate to Adjust Dye Bath pH

Dyeing-grade sodium acetate was used as a raw ingredient to modify the pH of dye liquors. In dyeing procedures that employ an acetate buffer system, sodium acetate is used with acetic acid to assist manage the pH of the dye bath; the desired pH value will vary according to the particular dye, cloth and stage of the dyeing process.

Function of the formula

In acid dyeing of nylon or wool, the pH of the dye bath may be adjusted by varying the ratio of sodium acetate to acetic acid. When dyeing cotton with reactive dyes, the pre-treatment, exhaustion and fixation phases have different circumstances. Therefore, different procedures must be set for each step and not one pH range for all colours.

Method of feeding

Dissolve the sodium acetate in water first, then add it in stages with continued circulation; if acetic acid is needed for fine-tuning, re-test the mixture after full blending. The automated dosing system needs the calibration of metering pumps, sensors and temperature compensation and must document measured values and dose volumes.

In-process inspection

Pay attention to precipitation, flocculation or abnormal foaming in the dye bath. Compare colour difference, levelness and colour fastness from batch to batch after dying. Over-dosing may affect the pace and depth of shade of dyeing; hence small scale testing have to be conducted before larger production.

Key Points for Raw Material Selection

Some dye solutions utilise sodium acetate sometimes to control the pH. The desired pH should be based on the processing needs of the dye and fabric and the pH level, colour difference and batch stability should be recorded at the small scale sample and mass production phases.