Other Contaminant in OCC and Mixed Waste Recycling, 2000 Pulping / Process & Product Quality Conference Proceedings

P. Seifert, W. South--Production costs of recycled paper and paperboards can be lowered by using proportions of lower cost, lower grade recovered papers. An example of this is using mixed waste as a substitute for old corrugated containers. As the level of mixed waste is increased the amount of "dead fines" raises significantly. To maintain final product quality as well as paper machine operation, a major portion of this "other" contaminant must be removed. As an important economic consideration, removal of the undesirable materials must be accomplished without the loss of the useable fibers. Conceptually it is advantageous to remove the "dead fines" early in the system to minimize the loss of the beneficial fines. The proposed system concentrates the "dead fines" with fractionation before their removal by washing. With the necessary yield reduction when a lower grade furnish is used, there must be considerable cost differential between the higher and lower grades of raw materials.