PREVENTING INK OVER-DISPERSION IMPROVES OLD NEWSPAPER DEINKING RESULTS

摘要

Over-dispersion of inks is becoming a greater deinking mill operating problem due to changes in ink composition (particularly greater use of vegetable oil-based inks and water-based inks) and increased closure of mill water-loops which can carry dispersed inks back into the system. Excessively small ink particles have a high tendency to redeposit on cellulose fibres reducing pulp brightness. Neutral deinking is becoming more common as mills seek to reduce the dispersive effects of high pH on stickies and ink particles. Use of less dispersive deinking surfactants to reduce ink dispersion in the pulper while still promoting efficient ink detachment from fibres.