Planetary ball mills can be used on a wide variety of materials for both dry and wet milling. Their unique planetary action increases greatly the impact energies achieved in other mills. Therefore samples are ground more quickly and to a finer final fineness. Several options of sample size, and number of milling positions are available to suit your laboratory.
Fundamental to all ball milling is the selection of the material of construction for the grinding set (the grinding bowl and milling balls). The material of construction selected must be harder than the sample material and any contamination from the grinding set must be accepted / tolerated. Up to seven different materials of construction are available to ensure almost all sample types can be successfully ground.
In the planetary ball mills, the grinding bowls rotate around their own axis, whilst orbiting around a central axis. Forces are exerted on the grinding balls and the sample, which are constantly changing direction and energy amount. Optimum grinding ball movements are obtained due to the design geometry and transmission ratios.
The grinding balls are carried up the inner wall of the grinding bowl and propelled off the wall; after crossing the grinding bowl, the balls and the material collide on the opposite side of the grinding bowl wall. The energy developed through the impact is several times higher than conventional ball mills. As a result excellent grinding results are obtained with much shorter grinding times.
The Fritsch Pulverisette Premium Line 7 planetary ball mill has been specifically designed for the production of ultra-fine powders and for the production of nano-particles. The two grinding bowls are sunk into the rotating disc, therefore allowing greater speeds of rotation, which hugely increases the impact energy during milling. The Fritsch Premium Line 7 ball mill, reaches centrifugal accelerations of up to 95 times the force of gravity. This further increases the speed of sample preparation and the final fineness, making ball milling down to the nano-range possible.