Conveying and breakup of a viscoelastic droplet in a dual-speed co-rotating non-twin screw extruder with multi-perturbation rings

Evolution and breakup of a tiny viscoelastic tracer droplet conveyed by another viscoelastic matrix fluid in a novel dual-speed, co-rotating, non-twin screw extruder with intermeshed multi-perturbation rings was studied to demonstrate the complex flow behavior and improved dispersive mixing. The visualization experiment was performed to reveal the conveying and breakup mechanisms using an aqueous solution of carboxymethyl cellulose aqueous (CMC-Na) as the matrix fluid and a drop of red oil-based ink as the tracer. The flow patterns were observed through a totally transparent barrel and the final morphologies of dispersed tracer filaments collected by a moving pulling film were recorded for statistical calculations. A time-dependent transient model was constructed and the numerical simulation using the finite element method along with the mesh superposition technique was performed to further examine the mixing details.