a first conveyor including parallel left and right roller paths of rollers, the roller paths being separated by a separating line, and the rollers of each path being oriented and guided to move in a direction parallel to the separating line, the first conveyor further comprising a respective drive with adjustable speed for each of the roller paths, each respective drive being operable for moving the paths at different speeds, the first conveyor being operable to rotate the plate elements placed thereon;

a suction apparatus positioned at the first conveyor, the suction apparatus including a first suction device positioned under the left roller path, the suction apparatus further including a second suction device positioned under the right roller path, the first and second suction devices being independent and physically separated from one another, the first and second suction devices being operable for simultaneously exerting on a same plate element different suction forces between the left path and the right path, the forces being directed downwardly towards and perpendicular to a plane of the first conveyor;

a frame supporting the first conveyor, the frame having guides shaped, positioned and operable to allow to move the first conveyor in a direction lateral to the separating line;

additional elements comprising at least one second conveyor located downstream of the first conveyor along a direction of conveying the plate elements, the second conveyor also having second left and right roller paths and a separating line between the second left and right roller paths, the second conveyor being operable to rotate the plate elements placed thereon and to move a barycenter of each plate element towards the separating line of the second conveyor;

the second conveyor being joined to the first conveyor and being disposed so that the separating lines of the first conveyor and the second conveyor are laterally offset from one another.