Bleaching of Nylon/Cellulosics is typically done with either reduction methods or sodium chlorite bleaching for the nylon since oxidation bleaches are harmful to nylon fibers. It should be noted that chlorinated treatments do have adverse effects on cellulose and should be used with caution.
The goods should be scoured prior to bleaching.
Any processing bath involving rayon should not exceed a pH of 9.0 as it may lead to saponification of the rayon.
- Scour goods in a bath containing 2% owg Orconol CHSA Conc™ and 2% owg tetrasodium pyrophosphate(TSPP) and run at 205°F(96°C) for one hour. For heavily soiled cotton, 5% owg of Caustic Soda may be used in place of TSPP, and Orconol CHSA Conc™ should be substituted with Orcoterge ALK-N Conc™ due to the high alkalinity of the bath. Drop bath and rinse well.
- In a fresh bath, bleach goods by adding 0.2oz/gal(1.5g/L) Sodium Chlorite* and 0.2 oz/gal(1.5 g/L) acetic acid and run for one hour at 205°F(96C). Drop bath and rinse until clear.
- In a fresh bath at 100°F(38°C), add 0.20 oz/gal(1.5 g/L) sodium bisulfite and 0.07 oz/gal(0.5 g/L) Orconol CHSA Conc™. Raise temperature to175°F(80°C) and run for 15 minutes. Cool bath to 140°F(60°C) and overflow rinse until clear.