Glycollic acid is used as the dyeing and tanning agent in the leather industry to improve the quality of products. Reasons are as following:
1. Its effective removal of calcium oxide (CaO) during the deliming;
2. It is a powerful complexing agent for acid pickling
3. It has an economic advantage by reducing the consumption of expensive dyes
In addition, nonvolatile, biodegradable glycolic acid can enhance the blending of dye colors, color distribution, and color saturation which also has low corrosion and better safety than many other acids. So more and more glycolic acid manufacturers use it for production.
The technical grade glycollic acid in the concentration of 70% is a solution mixed with 70% glycolic acid and 30% water which is suitable for the processes requiring pH controlling and low volatility.
1. During the in tannage process, glycollic acid is very effective for the adjustment of the pH of the immersing liquid which is crucial for sole leather and other plant tanning production. The effect of sodium salt as a masking agent is very good.
2. During the deliming process, glycollic acid can penetrate the leather quickly to reduce the operating time. Its features allow improving the texture quality by eliminating excessive fur expansion (fur expansion produces wrinkles and reduces tear resistance).
3. During the acid pickling process, the particular glycolic acid formula is helpful to the production. The glycollic acid, chromium, and alum mordant form a metal complex that contributes to fur painting.
4. During the dyeing process, the low volatility of glycollic acid makes its dosage lower than those volatile reagents such as acetic acid and formic acid; Its heat does not produce corrosive smoke so it is easier to maintain the pH level.