Numerical simulation of cavity roughness effects on melt filling in microinjection molding

Abstract

ABSTRACT:In microinjection molding, when dimensions of molded parts, and thus the cavity are small, cavity roughness may become significant for the filling of polymer melt. In this paper, cavity roughness effects on filling polymer melt flow into a thin circular cavity were investigated numerically with the aid of a newly developed inlet-velocity iterative procedure. The roughness effects for different mold and melt temperatures, cavity thicknesses, and injection rates were investigated. The trends predicted by the numerical simulation are in good agreement with those obtained from the experiment. When the surface roughness approaches a significant portion (e.g., 10%) of the cavity thickness, the effect of surface roughness becomes extremely pronounced especially at lower mold temperatures and injection velocities.

Overview of Injection Molding Technology for Processing Polymers and Their Composites

“…Progress has been made in obtaining the effects of mold temperature and injection melt temperature on the accuracy of micron injection molded products. [147][148] Xie et al found that mold temperature and injection speed are the main factors affecting micron injection welding marks. In the stage, ultrasonic vibration and physical vapor deposition (PVD) are used to process the corresponding films after molding, and even the strength of the thickness weld marks can be improved to greatly improve mechanical properties.…”

Numerical simulation and experimental verification of the filling stage in injection molding

“…Hassan et al [11] presented the effect of the viscous dissipation on the temperature of polymer melt flow inside a channel by using the finite volume method and the advancing front tracked by the marker and cell (MAC) technique. Ong et al [12] investigated the cavity roughness effects on filling polymer melt flow in a thin circular cavity, and the melt front is captured by the level set method. Recently, Li et al [13] proposed a self‐adaptive method that coupled the finite element method and the meshfree method in the arbitrary ALE description for numerical simulation of injection molding process.…”