Certain polymers require pelletizing to be carried out under conditions without water and moisture, so that the extrusion system should have sufficient cooling capacity to cater for in this process; some materials are sorted into shear-sensitive or heat-sensitive categories. SAT tandem extrusion system is deigned for such processes. Primary twin screw extruder provides mixing and dispersion without over-shear, lower speed single screw extruder provides enough cooling and pressure accumulation.