Increasing Yield of Recycled Fiber Processing Facilities via Chemistry, 2000 Pulping / Process & Product Quality Conference Proceedings

S. Shew, T. Fogarty, J. Marks--Advanced Screening and Cleaning system designs have been instituted resulting in significant improvement in recycled pulp quality. These improvements have generally not increased the yield of OCC and MOW recycled fiber processing facilities and in many cases has actually increased fiber rejects. This paper will highlight corrugating medium & linerboard mill case histories which outline how a patented chemical technology actually modifies surface-active forces between the recycled fiber and the wax & stickies adhering to the fiber. The mechanism results in stickies & wax being efficiently liberated from usable fiber. Such contaminants are then more efficiently removed by mechanical screens, centri-cleaners, and water clarification equipment, while the liberated "clean" fiber remains in the accept stream. Mill results show machine production gains of 6-10% (increased machine speed with fewer breaks), significantly lower dirt/stickies/wax counts, and elimination of a majority of paper machine stickies/wax deposition.