Upgrading of OCC Pulp by Flotation Fractionation, 1999 Recycling Symposium Proceedings

Jeong-Yong Ryu, Jong-Ho Shin, Steven S. –K. Ow

Air froth flotation was applied to OCC recycling process as a new pulp fractionation method and the effects of flotation were investigated in order to improve the pulp strength and drainage properties as well as optical cleanliness of testliner. Fines including inks, stickies, and inorganic substances in OCC stock furnish were efficiently separated by the flotation. Two pulp streams, top and bottom furnishes, were treated separately for making the two-ply testliner. The top stream was fractionated by flotation and the resultant accept was further treated with kneading, and was used for top furnish. In the bottom stream, after the second flotation, selective refining for the long fiber portion and an enzymatic treatment on the fines were separately carried out, and then, the long fiber and fines portion were blended again for bottom liner. These combination processes were found to be effective in improving strength, optical, and drainage properties of testliner based on 100% OCC.