Sieving

By definition, a sieve retains oversized particles and lets appropriate sized ones pass. Strictly speaking, rotary sieves should rather be called homogenizers, as they break down oversizes to a defined maximum size and do not retain any. The same applies to oscillating sieves, where transport energy is supplied either by centrifugal force or by an oscillating tool. Using rasp-like rotors milling is also possible, which may be necessary if hard lumps should be passed through the dyes.

Vibration dosing sieves are however proper sieves, separating oversized particles from the product.