Poisson ratio for BC and AM particles are derived from previously reported data , 24, rather than direct experimental measurements; • because of the reduced size of the geometry considered in the model, the Young modulus was decreased by an estimated factor of 1000; • neither the breakage of primary molecules inside the particles nor the fragmentation of the aggregates represented by the particles are considered in this model; • the recirculation circuit in the model is assumed to have a cylindrical shape to reduce particle clogging, whereas our laboratory experimental set-up uses a channel of variable width/depth (see Fig. ); • the shape of the extruder barrel and twin-screw is almost identical to that used in the experiment, although proportionally scaled down to make the computations tractable; • we considered the section closest to the extruder exit as the one giving origin to the filament whose microstructure properties are analyzed in detail in the following. We do not consider the relaxation of the microstructure that might arise from its cooling in contact with ambient air.