Evaluation of the Predictive Capacity of Viscosity Models in Polymer Melt Filling Simulations

A methodology for determination the inlet velocity in injection molding simulations

“…The component analized in this work is a test specimen injected in acrylonitrile-butadiene-styrene (ABS 750 from Kumho Petrochemical) [28] . In addition to its widespread use in industry, the ABS 750 was used in this work owing to the experimental and numerical validation of its rheological equations performed by the authors in previous studies [24,29] . The volume of the test specimen is 3 8.297 cm , and the specific mass of ABS 750 is 3 1, 033.40 g cm − according to the material manufacturer [28] , which leads to an average injected mass of 8.574 g. The ABS 750 was processed with an injection temperature of 235°C, a mold wall temperature of 10°C and an injection pressure of 25 MPa.…”

“…The Moldflow ® Advisor software simulates the flow of the molten polymer considering a non-Newtonian and compressible fluid under non-isothermal conditions. For more detailed clarification on the governing equations for the conservation of mass, momentum and energy for molten polymer flow, the reader is referred to Kennedy's work [31] for more details on the GHS mathematical approach and Miranda et al [29] for further details of the thermophysical properties used in the simulations.…”

“…The VOF methodology is a method for capturing the boundary that can consider more than one phase. The software considers linear correlations to estimate the viscosity and density at the interface between the molten polymer and the air confined inside the mold [32] : The reader is referred to Hétu et al [32] and Miranda et al [29] for more details on the VOF methodology.…”

“…The choice of a viscosity model must be done properly to ensure accuracy of the simulations. A previous study by Miranda et al [29] compared several viscosity models, confronting numerical and experimental results. The authors demonstrated that the constitutive viscosity model known as Modified Arrhenius Carreau (MACa) better capture the non-Newtonian behavior of molten ABS.…”

Measuring and Modeling of Melt Viscosity for Drug Polymer Mixtures

“…As an extension, the Bird–Carreau–Yasuda model describes the curvature between Newtonian and shear-thinning behavior more precisely by using an additional parameter [ 13 ]. In addition to these classic models, several modifications, like Sisko and Moldflow, were developed and their predictive capacity was compared, resulting in similar accuracy [ 20 ]. More complex mixtures of nanoparticle-filled polymers can be characterized using the common Carreau–Yasuda approach [ 21 ].…”