How to One-Bath Reduction Scour & Optical Whiten Rayon/Acetate Blends
Since rayon and acetate are both developed from regenerated cellulose, they have similar characteristics whereas both are sensitive to high pH’s at elevated temperatures. During scouring and bleaching of rayon/acetate it is important to stay below a pH of 9.5 where 9.0 is recommended. The processing temperature for acetate is lower than rayon and is in the range of 150-165°F(66-74°C). In order to minimize the risk of saponification of the acetate into its original cellulose form, it is wise to perform any processing procedures at these lower temperatures. Do to the alkali sensitivity of the rayon and its somewhat natural white state, a simultaneous reduction-scour-white procedure is used as follows:
- Enter goods into bath at 100°F(38°C) containing:
- Slowly raise temperature to 160-175°F(71-79°C).
- Add 0.5-1.0% owg Acetic acid and run for 30 minutes.
- Overflow to 125°F(52°C) and drop bath.
- Rinse well.