Glycolic Acid for Leather Dyeing and Tanning
The leather industry depends on glycolic acid as a dyeing and tanning agent to achieve high-quality results because it:
- Removes calcium oxide (CaO) efficiently in deliming
- Is a powerful chrome complexant for pickling
- Offers economic advantages due to reduced consumption of expensive dyes
Additionally, the nonvolatile, biodegradable glycolic acid:
- Offers better dye color matching, color distribution, and color intensity
- Has low corrosiveness
- Offers an improved safety profile over many other acids
Glycolic Acid Enhances Leather Dyeing and Tanning Processes
Glycolic acid 70% tech grade is a solution of 70% glycolic acid and 30% water, useful in processes that require pH control and low volatility.
- In tanning, glycolic acid is efficient for bath pH adjustment, which is critical in the production of sole leather and other vegetable tanning. Its sodium salt is effective as a masking agent.
- In deliming, glycolic acid penetrates hides rapidly to reduce operation time. Its properties improve grain quality by eliminating excessive pelt swelling that causes wrinkles and reduces tear resistance.
- In pickling, glycolic acid forms metal complexes with chrome and alum mordants, which is beneficial in fur and leather finishing.
- In dyeing, the low volatility of glycolic acid requires lower usage than volatile agents like acetic and formic acids; heat does not produce corrosive fumes, and pH levels are easier to maintain.
Glycolic Acid: The Best Choice for Dyeing
In several pilot tests that compared the use of glycolic acid with formic acid:
- Articles dyed with glycolic acid offered a more intense color hue
- Dye usage was reduced when glycolic acid was used in processing
- Hides dyed with glycolic acid were softer
- The physical properties of leather were not significantly changed when using glycolic acid