German to English Tech/Engineering Manufacturing Pulverizer for pharmaceutical produts

The client has had a translation into English with which he is not satisfied, and I have been asked to correct it. As well as the unsatisfactory English text, I have both the original German text and a French translation, in which the sentence containing the asked term has been translated as follows:

Pour n’engendrer qu’un minimum de particules fines lors du concassage, on utilise le côté couteau du rotor.

I don't speak German, and would appreciate an explanation in English (or French) of the term: I have a feeling that the blades are angled such that the product is hitting the flat of the blades, but I may be wrong.

Auf einer explosionsdruckstoßfesten Anlage eines Schweizer Arzneimittelherstellers werden staubexplosive Produkte aufbereitet, feinvermahlen und pulverisiert. Die Mühle steht im Anschluss an einen Schmelzextruder, wobei eine harte Substanz dem Mahlsystem über eine Zellradschleuse dosiert zugeführt wird. Um den Feinanteil beim Mahlen minimal zu halten, wird mit **der Messerseite des Rotors** gearbeitet. Der Vorteil dieser Anlage: Sämtliche staubexplosiven Stoffe der Kategorien St. 0 - 2 können darauf verarbeitet werden.

For information, the English version as received is:

Explosive dust products are prepared, finely ground and pulverized on an explosion pressure shock-resistant drug manufacturer. The mill is connected to a melt extruder, in which a hard substance is fed into the milling system via a rotary feeder. The rotors work with their blade sides in order to keep the fine fraction at a minimum during milling. The benefits of this system include: all explosive dust materials in category [unit size] 0 - 2 can be processed.