Forced Adsorption Contact - A New Way of Sticky Evaluation in Recycled Pulps, 1999 Recycling Symposium Proceedings

Thomas Krauthauf and Hans–Joachim Putz

Institut für Papierfabrikation

Darmstadt University of Technology

In recovered paper processing, the quantitative evaluation of stickies in pulp slurries continues to present a major problem, as to date it has not proved possible to realize the total detection of all stickies by means of a single method. Especially problematical is the fact that the materials deemed to be stickies often have very different characteristics. Because the only common characteristic of all stickies is their tackiness, a new adsorption-based method has now been developed that makes use of existing adsorption methods and refines them with the principle of "forced adsorption contact". Using model materials, it was demonstrated that an analyzer working in accordance with this principle is able to detect and gravimetrically quantify up to more than 80 % of Stickies introduced as pressure sensitive adhesives (PSA) into the pulp slurry. Therefore this principle could offer new possibilities for sticky detection in the future.