A Multiscale Simulation of Polymer Melt Injection Molding Filling Flow Using SPH Method with Slip-Link Model

Abstract

In this article, a multiscale simulation method of polymer melt injection molding filling flow is established by combining an improved smoothed particle hydrodynamics method and clustered fixed slip-link model. The proposed method is first applied to the simulation of HDPE melt in a classic Poiseuille flow case, and then two high-speed and high-viscosity injection molding flow cases in two simple long 2D rectangular cavities with and without a circular obstacle, respectively, are analyzed. For each case, the macro velocity results, and the micro average number of entanglements Zave and orientation degree S results are demonstrated and discussed, and the changing trends of Zave and S are analyzed. The results of the two injection molding cases are compared, and the influence of the obstacle on the injection flow at both the macro and micro levels is analyzed. Furthermore, based on the multiscale results, reason of some structural features and defects in injection molded products are analyzed.

Evolution of the Deformation‐ and Flow‐Induced Crystallization and Characterization of the Microstructure of a Single Spherulite, Lamella, and Chain of Isotactic Polypropylene

“…[244] This system can investigate the rapid evolution of multiscale and multilevel structures of polymers under the complex thermomechanical field during injection molding simultaneously. [244,[257][258][259] The novel crystallization behaviors of iPP, such as the crystallization kinetics, polymorphism evolution, and growth and orientation of lamellar crystals, are revealed systematically and efficiently via this system (Figure 50). Meanwhile, the in situ characterization is successfully utilized to efficiently quantify the crystallization time under various injection molding processing conditions, and processing windows are established directly.…”