AcidDyes
Acid dyes are a class of water-soluble, anionic dyes used primarily for protein fibers such as wool and silk, and for some synthetic fibers like nylon (polyamide). They are applied in an acidic bath, which promotes dye uptake; acidity is typically achieved with acetic or formic acid, or by the inherent acidity of the fiber. The dyes contain sulfonic acid groups that maintain water solubility and enable binding to amino groups in proteins or, in the case of nylon, electrostatic interactions and sometimes covalent bonding under heat.
Chemistry and application: Acid dyes are often azo- or anthraquinone-based and bear sulfonic acid groups. They
Fiber compatibility and performance: Acid dyes are favored for bright, clear hues on wool and silk and
Environmental and processing considerations: Dye baths often require salts and buffering to control exhaustion and uptake.