Caustic Concentration
Sodium hydroxide solution ranging between twenty and twenty-five percent active weight provides the chemical environment required for cellulose swelling within cotton fibres. Mercerization liquor performs this function by penetrating the fibre lumen to force a transition from the native kidney bean shape to a circular cross section. Higher alkali levels increase the lustrous appearance and dye affinity of the finished fabric.
Lower concentrations fail to trigger the physical restructuring of the crystalline lattice.
Process Requirement
Fabric immersion occurs within a trough containing the chilled aqueous reagent before mechanical stretching stabilizes the fibre structure. Cooling the bath to fifteen degrees Celsius prevents oxidative damage to the cotton during the rapid swelling phase. Automated titration systems monitor the alkalinity to ensure the concentration remains within specified tolerances during high speed production.
Maintaining temperature stability prevents irregular dyeing responses during subsequent wet processing stages.
Chemical Maintenance
Contamination from sizing agents and loose fibre debris reduces the efficacy of the reagent over repeated production cycles. Mills remove these impurities through continuous filtration and periodic replenishment of fresh sodium hydroxide pellets. Dosing the bath with wetting agents reduces the surface tension of the fluid to improve uniform penetration across dense fabric constructions.
Quality Verification
Laboratory personnel measure the density of the fluid using a calibrated hydrometer to confirm the molarity matches the technical specification for the target fabric quality. Incorrect concentrations produce uneven shrinkage and inconsistent light reflection across the width of a roll. Precise control of the active alkali content remains the single factor determining the degree of luster achieved in the final garment.
