Improving the Fines Performance of Recycled Pulps, 1995 Recycling Symposium Proceedings

John F. Waterhouse

Ye Xiao Liang

Institute of Paper Science and Technology

This paper considers the impact of fines on the papermaking potential of recycled pulps, and reports on our progress to improve the performance of the fines fraction of recycled pulps.

The papermaking performance of recycled pulps can be adversely affected by such factors as homification, contamination, loss of bonding potential, aging, and fiber damage. The impact of these factors on the fines fraction is quite severe, and as a result, they are only regarded as a filler material. Strategies to improve the papermaking potential of recycled pulps include fractionation where the fines are either discarded or later recombined with the refined long fiber traction; and caustic treatment of the whole pulp particularly old corrugated containers (OCC).

In the work reported here, fractionation is used to separate out the fines fraction (i.e., material passing a ZOO-mesh screen). The impact of sodium hydroxide treatment on drainage behavior and paper properties of blends of treated fines and the long fiber fraction are presented.