Typically, the fiber components of a wool/rayon blend would have been scoured in their raw form before making the blend. However, in some cases, soils or processing lubricants may be present that may require a scouring process. One important fact that should always be remembered is that wool, although very resistant to strong acidic conditions, is very sensitive to high alkalinity especially at elevated temperatures.
Wool scouring is typically carried out at temperatures below 140°F(60°C) with low cloud nonionic surfactants and/or anionic detergents sometimes in the presence of emulsified solvents. An alkali such as ammonia may be used, but the pH should not exceed 9 as the rayon component may begin to saponify, and temperatures in excess of 140°F(60°C) should be avoided .
- Enter goods into bath at 100°F(38°C) containing:
- Raise the temperature slowly to 130-140°F(54-60°C) and maintain for 20-30 minutes.
- Overflow, drop bath, and rinse.
- In cases where the wool/rayon is extremely contaminated, a second scour as above may be in order.