Enhancement of Stickies Removal from Recycle Streams by Agglomeration, 1996 Pulping Conference Proceedings

J. D. Hall and T. F. Ling Ph.D.

Betz PaperChem, Inc.

The removal of stickies from process streams containing recycled fiber is accomplished by mechanical separa-tion based on physical properties of the contaminant in relationship to the same properties of the associated fibers. Removal of stickies by size differential and density differential from the associated fiber mass has been refined and improved over the years to its current level of removal efficiency. Enhancement of the size differential can improve re-moval efficiency of contaminants using existing equip-ment. Contaminants such as contact adhesives, hot melt adhesives, toner inks, and waxes can be made to ag-glomerate to increase their size resulting in easier re-moval from a process stream using screens. Forward and reverse cleaning use density differentials to sepa-rate contaminates from the stock stream and larger particles are more easily removed than smaller particles of the same density. Agglomeration of contaminants can enhance the removal of these contaminants from the stock stream.