Dynamic Simulation Model for Breakup of Agglomerates in Polymer Melts
Takashi Moribe, James White
Mitsubishi Heavy Industries Ltd
USA

Keywords: Agglomerates, Breakup, Simulation

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Mixing is one of the most important components of polymer processing because the material formability and the product properties of the compound are highly influenced by mixing quality. In this work, we develop a dynamic predictive model for the deformation and breakup process of agglomerate in polymer melts. The Discrete Element Method (DEM) is employed to predict the behavior of particle-agglomerates on the dispersion process. Here, an agglomerate in a polymer melt is represented as an assembly of small spherical particle elements. The model is developed by taking into consideration the hydrodynamic drag force and the particle-particle interaction forces which induce flocculation and yield stresses in suspensions. During the mixing of agglomerates in polymer melts, agglomerates are dispersed and distributed in the matrix depending on the local stress fields in the fluid. The deformation and breakup process of coagulated particles is numerically investigated by using the DEM. It is observed that the agglomerate is deformed and split into many smaller fragments under shear and extensional flows. It is also indicated that the coalescence of particles occurs during the dispersion process. Erosion, breakup, and coalescence phenomena of the agglomerates in various flow fields are discussed.