a device for the preparation of plastics material for recycling purposes has a container with an upper inlet opening for the material . in the container , at least one tool rotates about the vertical container axis . this tool feeds the treated material through an outlet opening which is arranged at the bottom of the container and to which the housing of at least one screw is connected . that side wall of the feed opening at which the tool discharges defines a widening extending continuously towards the screw axis . this widening extends over part of the circumference of the screw turns so that the screw - side edge of this widening forms an uninterrupted shearing edge co - operating with the screw turns .