Bleaching removes residual lignin to raise brightness, and the constraint is doing it without degrading the cellulose that gives the sheet its strength.
That is why sequences are staged rather than aggressive, and why the protective chemistry matters as much as the oxidant.
What we supply
Sodium Chlorate, Sodium Percarbonate, Magnesium Sulphate and Sodium Hydroxide.
What we supply
Sodium ChlorateSodium PercarbonateMagnesium SulphateSodium Hydroxide Pellet
Sodium Chlorate The precursor to chlorine dioxide, generated on site. ECF sequences built on it are the mainstream route to high brightness without elemental chlorine.
Peroxide stages Peroxide-based stages brighten in alkaline conditions, and are the reinforcement or replacement chemistry where chlorine-based stages are being reduced.
Protecting the fibre Magnesium salts suppress the transition-metal-catalysed decomposition that would otherwise attack cellulose — brightness gained at the cost of strength is not a gain.