How to Bleach Cellulosics Using One-Bath Optical Whitener-Peroxide Bleaching Method
It is very important that the goods to be dyed are pre-scoured so they are free of any processing chemical additives such as sizes, waxes, oils, peroxide, chlorine, or natural contaminates. If rayon is part of the fabric blend, do not exceed a pH of 9.0 in any procedures. Due to the high alkalinity involved in most peroxide bleaching operations, optical brighteners should be chosen carefully for stability. Orco Synthrowite C-ALKS™ is designed to work in these conditions of extreme alkalinity.
- Enter goods in a bath at 80-100°F(26-38°C) containing:
3-4 % owb Hydrogen Peroxide 35%
1.0-1.5 % owb Sodium Silicate
0.25-0.5 % owb Caustic Soda(50%)
0.5-1.0 % owb Orcoterge ALK-N™
0.25 % owb Peroxide Stabilizer
0.75-1.0% owg Orco Synthrowite C-ALKS™*
* If the customer requests, a tinted version can be specifically formulated for the cast desired.
- Raise the temperature to 185-195°F(85-91°C) and run for 1 hour.
- Drop bath, rinse well, and adjust pH to 6.5-7.5 .
Pad-Batch: This process can be performed with or without bleaching auxiliaries.
- In a pad bath add .07-.13oz/gal(0.5-1.0 g/L) Orco Synthrowite C-ALKS™.
- Pad at room temperature and batch & cover for 8 hours. Wash a minimum of 4 ends hot on jig and scour off with acetic acid.
Pad-Steam: Pad at 105-115°F(41-46°C) and steam at 220°F(104°C) for 3-4 minutes using Orco Synthrowite C-ALKS™.