<p>Impacts with friction are today considered by a complementarity formulation or more abstract by prox-functions. In most cases the details are not described, and therefore, it will be subject of this paper. Frictional impacts are presented as part of an impulsive transport process applied for vibration conveyors. For this purpose we use the classical impact structure with compression, expansion and the relevant transitions. Ballistic free flights between impacts, sticking and sliding phases on the conveyor surface are possible. The approach using complementarities in graphical form gives an insight into the impact structure and additionally a good comparison with much more costly investigations.</p>