Usually, the first mixing extruder running at high speed has achieved good mixing effect and high output. The second extruder needs to be a single screw extruder with a larger diameter that can operate at low speed. Low screw speed can avoid excessive shear force, and the internal cooling system of the screw can prevent overheating and strong heat exchange capacity. The functional separation of the two allows operators to perform more flexible and predictable mixing processes and temperature control.