A Review of Ink Removal Techniques in Current Deinking Technology, 1990 Engineering Conference Proceedings

Deinked fiber can be a cost-effective component of a paper grade furnish, and has been successfully employed in the manufacture of various paper grades. However, today’s mixed wastepaper furnish to a deinking facility consists of a wide variety of papers printed using modern-day complex ink formulations and printing processes. Some of these inks are refractory in nature, making deinking of printed papers an extremely difficult task. The resulting non-dispersed ink particles appear as “specks” on the final paper, rendering it unacceptable for the manufacture of many printing and writing grades. Anticipated legislation mandating the use of recycled fiber as a certain fraction of all paper grades has lent an urgency to finding a solution to this problem. Progress is being made in finding ways to successfully remove stubborn inks, This paper reviews current deinking technology from the perspective of ink removal techniques. It deals with the various formulations of inks, and their application to paper by different printing processes, followed by a discussion of the means by which to remove them.