There is a study on the comparison of twin screw extruders and a batch mixer in the polymerization of caprolactam. A sodium metal initiator and 4-4'-diphenylmethane diisocyanate (MDI) as the activator were used. Our attention is given to (i) a modular intermeshing co-rotating twin screw extruder (ii) a modular intermeshing counter-rotating twin screw extruder and (iii) a modular tangential counter-rotating twin screw extruder Me consider the variables of screw configuration, temperature profile, screw speed, and throughput on polymer characteristics. It was found that the conversion of twin screw extruders with proper mixing segments is much higher than the internal mixer at low mixing times. This was seen as higher conversion in twin screw extruders than an internal mixer for the same mean residence time considered.