Modeling and Simulation of a Biopolymer Processing in a Single Screw Extruder

Modeling and numerical simulation of a biopolymer processing in a single screw extruder is developed. Polylactic acid (PLA) is one of the natural polymers proposed as a substitute for synthetic polymers because of the similarity in physical properties as well as processing conditions. The PLA behaves as a shear thinning fluid, in order to involve this feature the Power Law model is used as a constitutive equation and the temperature dependent viscosity is also considered. The model is validated comparing typical flow curves of a Newtonian fluid generated by the model with results previously reported in the literature. Finally, the drag flows and pressure flows are analyzed, the effect of the power index and the flow curves for Newtonian and non-Newtonian fluids are compared.