The present kinematic concept assumes both the barrel and the screw to move uniformly but in opposite directions. Equations 13, 14 and 15 were derived to describe the longitudinal flow, drag flow and pressure flow, resp., and equation 26 to describe the volume flow rate.
Sikora, R., & Sasimowski, E. (2022). A new kinematic model of the screw-based plastifying system. Polimery, 45(4), 264–270. https://doi.org/10.14314/polimery.2000.264