5. Conclusion

The co-mixer has long since proved itself as an excellent mixing tool, both in terms of dispersion and distribution. These qualities are due to its very particular operating mode, which allows the mixing fingers attached to the sheath to travel along the screw channels and, thanks to thread interruptions, to perform numerous flow separations and recombinations, associated with high local shear rates. Although it has given rise to far fewer scientific studies than other extrusion processes, its mode of operation is now well understood and, despite some residual shortcomings, more or less sophisticated models have been developed to help its optimum use. However, to the best of our knowledge, there is no commercial software dedicated to co-mixers, unlike what exists for bivision extrusion, for example.

From a technical point of view, recent developments have involved...