Common Auxiliaries and Their Functions
March 17, 2025
- Penetrant: Reduces the surface tension of the solution, making it easier for fibers to be wetted and penetrated.
- Detergent: Functions as a cleaning agent, facilitating the removal of dirt from fabrics and often used as a scouring and bleaching auxiliary.
- Caustic Soda (NaOH): A strong base, used as a scouring agent for cotton fabrics and also as a stripping agent. After use, it needs to be neutralized with acid before thorough rinsing.
- Soda Ash (Sodium Carbonate, Na₂CO₃): Serves as a water softener, a scouring agent for T/C fabrics, and a fixing agent for reactive dyes.
- Baking Soda (Sodium Bicarbonate, NaHCO₃): Can be used as a fixing agent for reactive dyes.
- Trisodium Phosphate (Na₃PO₄): Functions to soften water.
- Sodium Hexametaphosphate: Also functions to soften water.
- Sodium Silicate (Na₂SiO₃): Used as a scouring agent for cotton fabrics and as a stabilizer for hydrogen peroxide bleaching.
- Hydrogen Peroxide (H₂O₂): A bleaching agent that bleaches fabrics and can also be used as a deoxidizer.
- Sodium Thiosulfate (Na₂S₂O₃): Used as a scouring agent for cotton fabrics to prevent the embrittlement of cotton fabrics. It can also be used as a residual oxygen neutralizer and a dechlorinating agent.
- Sodium Sulfide (Na₂S): A dyeing auxiliary for sulfur dyes, which can fully reduce and dissolve sulfur dyes.
- Sodium Hypochlorite (NaClO): Serves as a bleaching agent and can also be used for stripping and cleaning vats.
- Table Salt (NaCl) or Glauber's Salt (Na₂SO₄): Used as a promoting agent for direct, reactive, and sulfur dyes, which can increase the dye uptake percentage.
- Sodium Hydrosulfite (Na₂S₂O₄): A strong reducing agent, used for stripping and reducing cleaning.
- Dispersant (or Diffusing Agent): Used as a dyeing auxiliary for disperse dyes, which can evenly disperse disperse dyes in the dye liquor to ensure the stability of the dye liquor.
- Glacial Acetic Acid (HAC): Used as a dyeing auxiliary for disperse dyes to adjust the pH value and as a neutralizer for alkalis.
- Ammonium Sulfate [(NH₄)₂SO₄]: Serves as an anti-alkali agent for disperse dyes and can also adjust the pH value.
- Levelling Agent: Enables dyes to be evenly adsorbed onto fabrics, achieving a level dyeing effect.
- Oxalic Acid: Can remove rust stains from fabrics.
- Fixing Agent (Fixing Agent Y or M): Ensures that direct dyes adhere firmly to fibers, thereby improving the color fastness.
- Softener: Binds to or adsorbs on the surface of fibers, functioning as a wetting agent and improving the hand feel of fabrics.
- Peregal O: Used as a levelling agent for direct and reactive dyes.
- Guangyouling: Removes oil stains from fibers.