USING THE FLOCCKY TESTER TO MEASURE RETENTION AID PERFORMANCE AND ITS EFFECTS ON SHEET FORMATION

摘要

Following laboratory testing, we concluded that the Floccky Analyzer can be used as an additional tool to assess the effects of polymeric retention aids on fines retention and sheet formation. Our data indicated the importance of the polymer "ratio", the ratio of polymer charge density to viscosity molecular weight, on fines retention and formation. Polymers with low ratios produced the highest Dynamic Drainage Jar (DDJ) retentions whereas polymers with higher ratios resulted in lower DDJ retentions. The high-molecular-weight, low-charge-density polymers produced strong floes by bridging flocculation which, when broken down under shear, were more difficult to reform once shear had ceased. On the other hand, high-molecular-weight, highly charged polymers, induced fines aggregation by charge reversal, and thus had inherently weaker bonds that broke up more easily under shear, but reformed once shear had ceased. More work is required with other types of pulps and polymers to evaluate the full potential of this method.