Velocity distributions in the nip and translational regions of a co-rotating twin-screw extruder

The positive displacement characteristics of a twin-screw extruder are often attributed to the intermesh of the two screws. Our objective was to measure velocity distributions in the nip and the translational regions of a co-rotating twin-screw extruder. The variation of axial and tangential velocity with screw rotation changed significantly from the translational to the nip region. Much higher axial velocity values were measured in the nip when compared with those measured in the translational region.