- The NaClO2 bleaching is performed after pH adjustment to 3.5 with an acid such as a formic acid. It provides soft hand with less embrittlement of cotton. Compared with the H2O2 bleaching, some insist that even bluish whiteness can be achieved with the NaClO2 bleaching.
Also, the NaClO2 bleaching is free from worries about pin-hole generation, as often occurs in the H2O2 bleaching. However, a harmful
chlorine dioxide gas is generated during the bleaching process, and therefore, suitable measures including the equipments need to be taken for metallic corrosion problems and dechlorination purposes. After bleaching, a dechlorination process needs to be provided. A trace chlorine which exists in fabrics reacts with nitrogen compound to form chloroamine, or cause yellowing of the fabrics when exposed to light and heat.
Note here that a special reducing agent, sodium thiosulfate (hypo), or hydrogen peroxide (so-called, cosmetic bleaching) is used for the dechlorination purposes.
- Sodium chlorite low-temperature activator -BRITE FB CONC