Abstract: Dough is extruded from a screw extruder through a nozzle, preferably a twin-slot nozzle, and an apertured blocking plate is placed between the tip of the extrusion screw and the nozzle assembly for making the pressure distribution across the dough in a pressure equilization chamber between the blocking plate and the nozzle more uniform and for controlling the rate of flow of the dough towards the extrusion nozzle slots. The blocking plate has two series of parallel channels arranged on two opposed arcs of the same circle centered on the central axis of the nozzle (the axis of the extrusion screw) and the series are symmetrical about a plane of symmetry of the nozzle.