New Waste Paper De-Inking Chemistry and Process, 1992 Pulping Conference Proceedings

Office waste paper will be an ever increasing source of high-grade chemical fiber as more offices respond to the environmental, economic, and regulatory demand to sort and recover their waste paper. But the variety of printing vehicles and the predominance of non-contact printed waste paper (laser/photo-reprographic) found in office waste paper, and the extremely wide particle size distribution 10- 500um) that is generated when office waste paper is repulped currently presents waste paper de-inking facilities with limited de-inking options.

ArcticWhite FiberTech Corporation (AWFT) has developed a washing/flotation de-inking process that integrates and optimizes system chemistry with current advanced equipment design. A non-caustic pulper chemistry improves defibering and ink detachment in the pulper. Optimized collector/frother flotation chemistry, used with flotation cells of advanced design, removes a greater number of ink particles and a broader range of ink particle sizes. Pilot-scale flotation de-inking trials processing laser computer printout (LCPO) and high laser/photo-reprographic printed office waste paper were conducted to compare our flotation reagents to other commercially available flotation reagents. Image analysis data showed 93-95% flotation ink removal efficiency for the our flotation reagents and 58.4% and 54.2% flotation ink removal efficiency for other commercially available flotation chemistries.

Full-system commercial-scale de-inking trials were conducted. Processing high laser/photo-reprographic printed office waste paper, without the use of high energy dispersion, our integrated de-inking approach achieved 97.3% ink removal efficiency, and a fiber brightness of 81.7 (without bleaching).

Our integrated de-inking process provides increased flexibility and capabilities for a de-inking facility. It increases the choice of waste paper furnishes a facility can process by providing the capability to process difficult to de-ink waste paper such as office waste paper, while achieving net cost and energy savings.