The Fritsch Pulverisette 9 disk mill (or vibrating cup mill) operates on the principle that the grinding set is fixed on a freely vibrating structure and the grinding media (the disc and the ring(s)) inside the grinding set are accelerated by centrifugal force. The sample material is milled by a combination of impact and friction forces, which (depending upon the material) can reduce the particle size down to 10-20μm. The grinding sets are closed and sealed in the vibrating cup mill during operation and this prevents losses during either wet or dry milling. Rotation speeds from 600 to 1,150rpm can be selected in steps of 50rpm.
The Pulverisette 9 may be used to prepare samples with a maximum feed size (depending upon the material) of 12mm and process up to 250ml sample volumes at a time. The Pulverisette 9 is a free standing unit and the grinding set slides in and out of the instrument to prevent bending when loading the instrument. For ease of use, the grinding set is mounted on a plate with handles on each side, which enables comfortable and easy location and loading of the vibrating cup mill, prior to milling.
The Fritsch Pulverisette 13 laboratory disk mill, has been specifically designed for batch or continuous grinding of very hard and brittle materials. The maximum feed size is around 20mm edge length and the final fineness achieve can be varied from 12mm down to 0.12mm. During operation, the sample material is ground between two counteracting grinding disks, which have radial blades. These radial blades, both shear and compress the sample material in the inner chamber, before the material is finely ground in the outer chamber of the grinding disks. The final fineness, is determined by the gap setting (or distance) between the outer edges of the grinding disks.
The Pulverisette 13 laboratory disk mill, has a maximum throughput of up to 150Kg/hour depending upon the desired final fineness and the hardness of the material being milled. This relatively large throughput enables the disk mill to be used on a pilot plant scale or in small scale production facilities.