(EN) In a method of carrying out continuous preparation processes on tightly meshing extruders rotating in the same sense such as twin-screw and multi-shaft screw-type extruders, the extruder is operated at a screw speed of rotation of at least 800 rpm, accompanied with a simultaneous increase of the so-called "torque density" (M.sub.d /a.sup.3) of at least 11 Nm/cm.sup.3 and a volumetric ratio (Da/Di) of at least 1.5.