The WRG range of water-ring pelletizers (photo) for making pellets of polystyrene (PS) and polyoxymethylene (POM) has the advantage that the cooling and conveying medium (water) does not come into direct contact with the die plate. The rotating knives cut the extruded strands of melts into pellets. Centrifugal action of the knives sends the still-hot pellets into the rotating water ring, which cools them and conveys them out of the pelletizer hoods. Favorable operating costs result from: the low energy requirement for the die plate and the rotor drive; the negligible wear on the knives and the die plate; and the simple and rapid startup process. A WRG 320 has been delivering 5,000 kg/h PS pellets for two years, and a 9,000 kg/h unit has recently been delivered. — Coperion GmbH, Stuttgart, Germany