Pressure Filtration of Cellulose Fibres

The compressional rheology of cellulose fibre suspensions has been studied using a pressure filtration technique. The dewatering of these systems is described in terms of various key properties of the suspension, including the compressive yield stress, permeability and solids diffusivity, permitting a quantitative characterization of the consolidation process. We investigate, as a particular example, the effect of a commercial debonding agent additive on the compressional properties of a fibre suspension. Such agents are used commonly in the production of hygiene products where they are added to decrease the strength of fibre-fibre bonds. Here, we investigate their effect on the compressive response of fibre suspensions as an example of how measurements of this type can be used to characterize the effect of additives on bulk properties. The results indicate that the addition of debonder lowers the dewatering tendency for a broad range of fibre concentrations, and leads to the formation of flow channels in the compressed fibre suspension