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After a grinding time of 90 seconds, an aliquot of sample has been used to determine the fineness with Vibratory Sieve Shaker ANALYSETTE 3 Pro and a test sieve of 63 µm.

Already 96 % of sample use to be < 63 µm as desired. Because the sample used to start sticking lightly to the grinding set, we don’t recommend proceeding dry grinding.

Sticking uses to happen after the majority of particles reached a fineness of < 20-30 µm. Interacting forces between fine ground particles will become bigger as their own g-force. Therefore, particles will stick to each other and become compressed by the used grinding set. These clusters of particles also contain bigger particles which will not be ground any further.

For this, we recommend to add e.g. solvents (for a faster evaporation) and proceed grinding for maximum 3 minutes to maintain 100 % < 63 µm. It is also possible to interrupt the grinding process after e.g. 60 seconds and separate the desired fraction of particles by sieving or sifting. Afterwards, the coarse fraction can be ground without sticking effects.