Isothermal transient startup of a starved flow modular co-rotating twin screw extruder

A model for flow start‐up of a Newtonian liquid in an initially empty modular selfwiping co‐rotating twin screw extruder is developed. The changes of length of fill in front of the die and kneading disc block elements and output flow rate with time were predicted for various modular screw configurations. Experiments were also carried out on a laboratory modular machine with windows to verify predictions. Generally, good agreement with the flow analysis was found.