THE EFFECT OF SUSPENSION CROWDING ON THE INPLANE DISTRIBUTION OF FILLER IN HANDSHEETS

The distribution of calcium carbonate filler retained by mechanical en trapment over a range of crowding number was investigated for softwood and hardwood pulps. Measurements on loaded sheets and on sheets for w hich the filler had been removed show that the distribution of filler in the plane of the sheet is non-uniform and dependent on the degree o f crowding in the suspension. Analysis of rite results using statistic al geometric models for fibre contacts and inter-crossing distances be tween fibres in suspension gives new insight into the mechanisms of me chanic at retention of filler.