Elimination of fluorescent agents contained in old papers by peracetic acid

摘要

The reduction and/or elimination of the fluorescence of the cellulose fibers is carried out by destroying the fluorescent agents with peracetic acid. The reduction or/and elimination of the fluorescence of the cellulose fibers in old papers and more specially in recycling paste of old papers is carried out by adding peracetic acid in one or several places of the recycling setup, before the setup such as the pulp, the heating screw, the thickening screw and/or the hot grinder, or if necessary before or after the step of ink removal, or after the setup in one or several whitening towers.