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

Area of Science:

• Polymer Science and Engineering
• Computational Fluid Dynamics
• Materials Science

Background:

• Injection molding is a key manufacturing process for polymers.
• Understanding polymer melt flow dynamics is crucial for product quality.
• Existing simulation methods may not fully capture microstructural changes during filling.

Purpose of the Study:

• To develop and validate a multiscale simulation method for polymer melt injection molding.
• To analyze macro and micro-level flow behaviors, including entanglement and orientation.
• To investigate the influence of geometric features, like obstacles, on injection molding processes.

Main Methods:

• A multiscale simulation approach combining improved smoothed particle hydrodynamics (SPH) and a clustered fixed slip-link model.
• Simulation of High-Density Polyethylene (HDPE) melt in Poiseuille flow and two-dimensional rectangular cavities.
• Analysis of macro velocity, average entanglement number (Z_ave), and orientation degree (S).

Main Results:

• The multiscale method successfully simulated HDPE melt flow in various configurations.
• Macro velocity, Z_ave, and S were analyzed, showing distinct trends during filling.
• The presence of an obstacle significantly impacted flow behavior at both macro and micro scales.

Conclusions:

• The developed multiscale simulation method provides insights into polymer melt flow during injection molding.
• The study correlates simulation results with potential structural features and defects in molded products.
• This approach aids in optimizing injection molding processes and predicting product quality.