Comminution plays an important role in industrial processing of various materials especially in the field of recycling. However, there is scanty knowledge about comminution of non-brittle materials in contrast to brittle materials. Apart from few research works, they are based on empirical studies and improvements of the comminution machines. Therefore, the tame; of DFG Project "Comminution of non-brittle materials" is to specify the occurring cutting and shearing processes. At the chair of construction in mechanical engineering and appliance at the University of Kaisenlautern, the single-cut process of polypropylene and aluminium between the rotor and stator cutter of model cutting mill was analysed. In particular, cutting energy, cutting forces and mechanisms were investigated. Examinations were carried out by a systematic variation of the machine parameters like rotor cutter wedge angle beta(R), cutting clearance s, cutting edge radius r and circumferential speed v, as well as the parameters width b, thickness d and the segment length of the cutting material l. (C) 2004 Published by Elsevier B.V.