Mercerowanie

Mercerowanie, or mercerization in textile technology, is a chemical treatment of cellulose fibers, most notably cotton, with concentrated sodium hydroxide (caustic soda). When applied under tension, the alkali causes the cellulose to swell and realign into a more uniform crystalline form, improving dye uptake, luster, and dimensional stability.

The process uses typically 18–30% NaOH at ambient temperature to mild heat, with the fiber held under mechanical tension to prevent shrinkage. After treatment, the alkali is neutralized and the fabric washed, often with an acid neutralizer such as acetic or sulfuric acid, and then rinsed.

Mercerized cotton shows increased dye affinity, deeper and more uniform shades, and a brighter appearance. The surface becomes smoother and the fabric may exhibit improved wet strength and resistance to wrinkling. The exact outcomes depend on concentration, time, temperature, and the level of tension.

Mercerization was developed for cotton by John Mercer in the 1840s. It can also be applied to some other cellulose-based fibers. Because it uses caustic chemicals, proper handling and complete neutralization are essential to avoid fiber damage or skin irritation and to manage wastewater.