Sodium hydrosulfite – A Core Assistant in Bleaching and Reduction Dyeing in the Textile Industry

                           Sodium hydrosulfite – A Core Assistant in Bleaching and Reduction Dyeing in the Textile Industry

Sodium hydrosulfite is widely used in the textile industry, accounting for over 60% of its total usage. It primarily utilizes its strong reducing properties to achieve three main functions:

1. Fabric Bleaching: Used for low-temperature (40-60℃) bleaching of natural fibers such as cotton, linen, silk, and wool, as well as synthetic fibers such as polyester and nylon. It gently removes natural pigments or residual dyes from fibers without damaging the fiber structure.

2. Dye Reduction and Dyeing: Reduction dyes (such as indigo) require sodium hydrosulfite to be reduced to a soluble "leuco" form before they can be absorbed by fibers. After dyeing, oxidation fixes the dye onto the fibers, which is crucial for the "indigo dyeing" process in denim.

3. Removal of Clothing Defects: Low-concentration sodium hydrosulfite solutions (0.5%-2%) can reduce "color bleeding" or "dyeing defects" that occur during washing, achieving a stain removal effect.