CHARACTERIZATION OF WET MASSES USING A MIXER TORQUE RHEOMETER .1. EFFECT OF INSTRUMENT GEOMETRY

Two laboratory-scale, instrumented mixer torque rheometers have been used to monitor the rheological behaviour of a model wet mass. The two instruments differed in the arrangement and gearing of their mixing blades and the results obtained from each were not identical. In both rheometers liquid distribution was identified as being responsible for the initial variation in the rheology of the wet mass and the mechanism of that distribution process depended upon the level of liquid saturation. The rate of liquid distribution was different in each of the two rheometers and this has been attributed to the different mixing intensities of the two instruments, Equilibrium data showed similar trends, thus indicating a means by which different mixing processes could be compared. A cumulative energy of mixing term was derived to describe the energy input during the mixing process.