This procedure bleaches out the black hairs that are commonly found in wool without the generation of a sulfurous odor. It is typically necessary to perform a black hair bleaching process if white, off-white, or pastel shades are desired.
- Enter prewet goods* into bath containing:
- 6 g/L Ferrous Sulfate
- 4 g/L Orco Bleach Assist ASC™
- X g/L Formic Acid to pH of 3 if necessary
- Set bath at 110°F(43°C) and circulate for 15 minutes.
- Slowly raise temperature to 175°F(80°C) and hold for 60 minutes.
- Drop bath and rinse at 175°F(80°C) for 20 minutes.
- Cold rinse at 70-80°F(21-27°C) for 20 minutes.
- Drop bath and refill.
- Enter goods into fresh bath containing:
10 g/L Tetrasodium Pyrophosphate(TSPP)
10 ml/L Hydrogen Peroxide 35%
X ml/L Ammonia if needed to pH of 8-8.5
- Raise temperature to 175°F(80°C) and hold for 60 minutes.
- Re-acidify if necessary with either acidic or citric acid.
Note: If an overall lighter effect is required, repeat steps 7-9.
* Prewetting is recommended with 2-2.5% owg Orconol CHSA Conc™ in a separate bath or may be added directly to the first bath in step 1.