Nine different test devices have been discussed in this report and beside them other designs are possible. Now the question arises which particular device should be selected? Obviously this depends on the objectives of the planned investigations. For this reason the following aspects have to be considered for a decision:
- Are the investigations focussed on the particle breakage behaviour and the primary breakage or on the secondary breakage?
- What kind of material should be tested: brittle materials as minerals and the like or ductile deforming materials such as polymers?
- Is it of interest to vary widely the particle size and what size range is to be investigated?
Each researcher has to decide what contribution to the comminution science or what improvement to the technology he wishes to perform. Nevertheless it seems reasonable to suggest two test devices for measuring the data for secondary breakage (fraction of broken particles, breakage function, increase of the specific surface and the liberation grade) for wide applicability.
1. A piston press with different working units for testing brittle particles in the single particle situation above 1 mm and for interparticle stressing above 10 pm. Special working units for different temperatures are possible, therefore also polymer particles could be stressed at low temperatures. The piston force should be at least 200 kN, but the hydraulic system has to be sufficiently sensitive that a force of only a couple of kN could be applied accurately. The advantages of such a device are the following: