Carbon nanotube (CNT) based nanocomposites have been developed to obtain excellent mechanical properties and functionalities. The twin-screw extrusion (TSE) processing for improving the dispersion of CNT is not effective solution due to the limited residence time. Hence, expected properties have not been achieved because dispersion of CNT is poor. This describes that shear flow which is dominated mainly in TSE cannot disperse the CNT effectively. Extensional flow which is caused in converging section has been attracted as the effective solution for enhancement of nanofiller dispersion. However, the dispersion effect of extensional flow hasn’t been revealed in case of nanocomposite system. In this study, we suggest a new screw design induced extensional flow for TSE based on our research achievements. CNT dispersion is enable by extensional flow induced high pressure drop and high-speed flow through the small hole. This technique applied to disc type segment which we called Blister Disk (BD) with many small holes. However, melted polymer leaked out between the gaps of this two discs. To avoid this leakage, separated BDs were modified to fixed type BD (XBD) by using ball bearing. To investigate the dispersion efficiency of XBD, that of neutral type Kneading Disc (KD) and separated BD are compared in case of CNT based polypropylene (PP) nanocomposite. The dispersion state of CNT is investigated through morphological observation, rheological-, electrical- and mechanical measurement. The morphological assessment shows CNT dispersion is improved by using XBD. Therefore, the electrical conductivity measurement also shows low volume resistivity when XBD is used. The tensile strength also improved slightly. These reason could be the effect of extensional flow. Furthermore, the resin temperature at outlet of TSE by using XBD can be reduced 5 °C by compared with KD against the same specific mechanical energy (SME). Therefore, XBD can provide to high quality compounding in respect to enhancement of CNT dispersion and reduction of shear heating.