In this study, we consider two different material injection scenarios. It is common to observe in experiments, first injecting the three polymers into the extruder to melt them, and then add the AM and carbon nanofibers. By following what is done in experiments, we considered a first type of material injection method in our simulations called "sequential injection scenario", which consists of first inserting BC particles into the extruder, then AM particles at the same inlet (see Fig. , left). We follow the experimental works carried out in our laboratory in maintaining the mass ratio of BC to AM at 0.45 and 0.55, respectively. In the sequential injection scenario, we insert BC particles for 7 million timesteps (M 𝛥𝑡) from simulation time t = 0, so that the BC particles almost fill the conical extrusion part. Then, we stop adding the BC particles and start adding the AM particles at the same inlet as before, for another 7 M 𝛥𝑡.