Sodium Hypochlorite

Bleaching Reaction

The chemical works by releasing active oxygen that breaks down the natural color molecules in the raw fiber. During this reaction, sodium hypochlorite must be kept in an alkaline state to avoid the release of toxic chlorine gas and to prevent fiber degradation. Acidic conditions would lead to rapid loss of fiber strength.

Fiber Protection

If the bleaching bath is not carefully monitored, the cotton fibers can undergo excessive oxidation. This degradation weakens the cellulose chains, resulting in a fabric that tears easily and has low durability. To prevent this, mills are increasingly replacing sodium hypochlorite with hydrogen peroxide, which is more environmentally friendly.

Quality Monitoring

Technicians check the chlorine concentration and fabric whiteness index before and after the bleaching process. Measuring the fluid pH and residual chlorine ensures that the sodium hypochlorite has been completely neutralized and rinsed from the fabric. Any remaining bleach would cause yellowing and strength loss during subsequent drying.