Extension of Einstein's Law for Power-Law Fluid to Describe a Suspension of Spherical Particles: Application to Recycled Polymer Flow

Ghinwa El Hajj Sleiman (1) , Isabelle Petit (1) , Nadine Allanic (1) , Sofiane Belhabib (1) , Yannick Madec (1) , Rémi Deterre (2, 3)

1 GEPEA - Laboratoire de génie des procédés - environnement - agroalimentaire
2 GEPEA-OSE - Optimisation - Système - Energie
3 GEPEA-MAPS2 - Matrices Aliments Procédés Propriétés Structure - Sensoriel

In this work, Einstein's equation is extended considering a power-law suspending fluid without any Newtonian approximation. To validate the developed equation, an experimental setup is carried out. Polypropylene (PP) and polyethylene (PE) are injected at different volume fractions. The pressure drops measured in a cylindrical die are analyzed. The results show that the developed relationship allows better prediction of the viscosity of PP/PE blends compared to existing laws. During the recycling of PP, some pollutants are likely to be present in the polymer, mostly PE which tends to form a heterogeneous melt with PP. At low volume fractions, PE disperses mostly as solid spheres in PP due to its higher viscosity, but the viscosity of the PP/PE mixtures is hard to predict. Several studies have derived equivalent viscosity equations for dispersed spherical suspensions in shear-thinning polymers. Nevertheless, these equations mainly refer to Einstein's equation for suspended spheres in Newtonian fluids. POLYM. ENG. SCI., 59:E387–E396, 2019. © 2019 Society of Plastics Engineers

Domaines: Polymères; Génie des procédés; Matériaux

Ghinwa El Hajj Sleiman, Isabelle Petit, Nadine Allanic, Sofiane Belhabib, Yannick Madec, et al.. Extension of Einstein's Law for Power-Law Fluid to Describe a Suspension of Spherical Particles: Application to Recycled Polymer Flow. Polymer Engineering and Science, 2019, ⟨10.1002/pen.25070⟩. ⟨hal-02464187⟩