Greige Storage Conditions Impact on Subsequent Dye Absorption
Uncontrolled greige storage triggers moisture migration, lipid autoxidation, and sizing retrogradation, which impair surface wettability and cause severe dye absorption variances.
Carboxyl Group Repulsion
Electrostatic Force
Negative electrostatic fields generated by ionized functional groups create mutual kinetic resistance between adjacent polymer chains or dye molecules in aqueous media. Anionic charges along oxidized cellulose chains drive carboxyl group repulsion, altering fibre swellability and chemical receptivity during wet processing. Alkaline treatments ionize carboxylic acid sites into negatively charged carboxylate anions on cotton fibre surfaces.
The resulting charge repulsion causes micro-fibrils to expand, increasing internal pore volumes and water accessibility in mercerized cotton.
Dye Rejection
Anionic dye molecules experience strong electrostatic resistance when approaching modified cellulosic surfaces carrying identical negative charges. Direct and reactive dyes containing sulfonate functional groups suffer reduced exhaustion rates when carboxyl group repulsion increases on over-bleached or oxidized cotton goods. To overcome this mutual charge barrier, processing plants add sodium chloride or sodium sulfate to the dye liquor, neutralising negative surface charges and allowing dye diffusion.
Carboxymethyl cellulose size coatings similarly exert electrostatic resistance against anionic softeners, forcing finishing mills to select cationic or non-ionic chemical formulations. Bath conductivity and pH measurements verify ionic charge balances before long liquor dyeing.
Finish Attenuation
Negatively charged resin particles fail to exhaust uniformly onto heavily oxidized cotton fibres during padding. Carboxyl group repulsion forces anionic finishing emulsions away from the fibre surface, producing patchiness and low fastness values on treated fabrics.
Charge Balance
Cationic pre-treatments neutralize surface negative charges on oxidized cellulosic substrates. Carboxyl group repulsion vanishes when quaternary ammonium compounds bind to ionized carboxylate sites, restoring uniform dye absorption across damaged fabric panels.