Pilot Paper Machine Trials on the Retention of Fresh and Recirculated Fines with a PEO/Cofactor Retention Aid System

摘要

The retention efficiencies of fresh and recirculated (or contaminated) thermomechanical pulp fines by a poly(ethylene oxide)/cofactor (PEO/CF) retention aid system were compared on a high-speed pilot paper machine. The effect of the state of PEO entanglement was studied as well. The results showed no significant difference between these two kinds of fines on the time scale of a trial (about one hour). Consistent with what has been found in previous studies, the results showed that entangled PEO was more efficient than disentangled PEO, both for fresh and recirculated fines. During the first 12 minutes after PEO/cofactor injection, the fines retention increased by 40—50% for entangled PEO, but only by 20-2 5% for disentangled PEO.