6. Conclusions and outlook

Over the past 30 years, the understanding and modeling of extrusion die flows have enabled us to make considerable progress in tool design and optimization of operating conditions. However, this approach is by no means exclusive, and will certainly never completely replace the experience of the skilled craftsman.

Indeed, no matter how sophisticated, a calculation model is always based on restrictive assumptions (in particular, the choice of behavior law and conditions at tool walls, especially sliding or adhesion) and cannot claim, on its own, to answer all the problems encountered in daily practice. These methods should therefore be seen as aids to design, which can produce results that are all the more convincing when combined with solid experience and, above all, an excellent sense of physics.

For a long time, the calculation methods...