device for processing material by mixing and / or plasticization or agglomeration a device for processing material by mixing and / or plasticization or agglomeration has a screw housing , in which at least two screws are situated adjacent to one another . the screw channels are engaged with one another . the screws are driven to rotate by at least one motor . the screws are supplied with the material through an intake opening of the screw housing and the processed material leaves the screw housing through at least one outlet opening . an apparatus is provided , which in operation of the device provides the gap which exists between adjacent screw channels of the screws alternately with a periodic enlargement or reduction , which is superimposed on the rotational movements of the two screws . in the method for material processing , the material , in addition to the compaction which is caused by the conveyance action of the screws , is subjected to periodic squeezing by the screws .