SOURCE VARIATION IN THE WET MASSING (GRANULATION) OF SOME MICROCRYSTALLINE CELLULOSES

The role of particulate and surface energetic properties of powdered microcrystalline celluloses on their rheological behaviour during the wet massing stage of the granulation process has been studied using an instrumented mixer torque rheometer. The rheometer identified differences in 'consistency' of the wet masses produced from mixes of materials from different sources. Examination of some of the surface energetic properties of the three celluloses using immersional calorimetry indicated a similar degree of physico-chemical association with water for all of the materials. However, studies of their particulate characteristics using SEM and surface area techniques revealed differences in the materials which corresponded very well with the observed rheological behaviour.