What exactly is Extensional – Elongational Mixing?
This is a very well-known characteristic of viscoelastic materials, encountered whenever a viscoelastic polymeric material is hot melted and converged (velocity acceleration) and then diverged (velocity deceleration), creating spiked elongating forces that can break up particles by creating multiple smaller elongated oblates, which then are further reduced by subsequent convergence. The change in velocity creates localized changes in shear rates and stresses which are more efficient at breaking up agglomerates to increase surface area versus conventional sustained high shear alternatives. 2.
