Acetate generally is received by the manufacturing plant in a clean white form which generally does not require bleaching. However, bleaching may be necessary to obtain a certain white desired by the customer. Bleaching procedures generally require initial steps for foreign material removal from the fiber as the actual bleaching process may trap the soils and stains. These steps include desizing, mercerizing, and scouring. The goal of bleaching is to attain the maximum whiteness with minimum fiber strength loss, in addition to the removal of oils, waxes, and sizing, foreign matter, and promotion of fiber absorbency.
Scouring of Acetate
Scour goods for 30-45 minutes in a bath at 170°F(76°C) containing:
1.0% Orconol CHSA Conc™ on weight of goods(owg)
0.07 oz/gal(0.5 g/L) Tetrasodium Pyrophosphate(TSPP)
Drop bath and rinse goods well.
It is very important that the pH does not exceed 9.0 as saponification of the fiber may occur.
An optional procedure is to run goods for 30 minutes in a bath at 170°F(76°C) containing 1-2% owg Anionic Wetting Agent. After scouring, drop bath and rinse well.
Bleaching of Acetate
During the bleaching of acetate it is important that the pH does not exceed 9.0 which may cause saponification of the fibers. In a bath at 150°F(66°C) add:
3.75 lb/100gal(.37kg/100L) Hydrogen Peroxide 35%
1.0% owg OrcoTerge ALK-N Conc™
2 lb/100gal Peroxide Stabilizer
Run for 1 hour, drop bath, and rinse warm.