The extrusion of compound billets with fibrous oriented filaments resulted in an inhomogenous arrangement of the filaments in the profile due to an unequal flow rate along the cross section. The material in the core of the billet has a higher speed compared to the material at the edge of the billet which leads to an advance of the filaments. For this reason only 90% of the profile volume could be used for further processing. Thus, meaning a substantial economic loss.