Use of Chemi-Mechanical Office Waste Deinking Systems to Recycle Lower Grade Wastepapers, 1994 Recycling Symposium Proceedings

Frank J. Sutman

Use of lower grade off ice wastepaper furnishes to produce printing and writing quality pulp would allow a major reduction in deinking system operating cost. Pilot chemi-mechanical office waste deinking trials were run to compare the deinked pulp quality obtainable from a well-recognized lower grade furnish (Weyerhaeuser Office Pack) to a standard high grade furnish (Sorted White Ledger (PS-40)).

The lower grade furnish produced deinked pulp with a TAPPI dirt count of 6 ppm and an unbleached brightness of 77%. The pulp brightness was raised to 85% with a 2-stage peroxide/FAS bleaching process. The Sorted White Ledger produced a TAPPI dirt count of 10 ppm and an unbleached brightness of 84%. The stickies contents of the two pulps were evaluated by three different methods and were found to be equivalent and quite low.

Equivalent quality pulp was obtained from the two different furnishes using the same deinking process, provided that an appropriate post-bleaching process was added to eliminate the brightness drop associated with the dyes in the lower grade furnish.