Peroxide, Reductive Bleaching of Mixed Office Waste to High Brightness
A mixed office waste furnish containing 3-4% groundwood, 0.5-1% brown fiber and high color content, was successfully bleached to 82-85 ISO. The starting furnish, containing 16% colored fiber initially, underwent pulping, cleaning, screening, flotation and washing at a pilot facility before laboratory bleaching. The study looked at the effects of peroxide charge, caustic ratio, consistency, temperature, peroxide stabilizers and sodium hydrosulfite versus FAS. laboratory generated color mix was added to the initial pulp in order to achieve total color content of 33% for evaluation of a worst case scenario. Chemical charges were varied from 0.5-1.0% for peroxide and 0.4-0. 5% for FAS depending on color content of the furnish and the consistency of the peroxide stage. Sodium hydrosulfite was used at a constant 1% charge.
Peroxide, Reductive Bleaching of Mixed Office Waste to High Brightness