Investigation of an Innovative Technology to Advance Injection Molding of Hot Runner Systems

K. Alqosaibi, C. Thakur, H. Noor, A. Duhduh, J. Coulter
Lehigh University,
United States

Keywords: injection molding, hot runner systems, Rheo drop

Summary:

A novel technology “Rheo drop” is developed to advance the process of injection molding of hot runner systems. This technology allows precise control over shear rate applied to the polymer melt during the injection molding process in the hot drops, thus, viscosity can be tuned to prevent cold slug formation as well as enhancing the quality of molded parts. In addition, this technology enables processing the materials at lower temperatures, which can be beneficial for temperature sensitive materials to prevent thermal degradation. Analytical and experimental investigations were performed to validate the developed “Rheo drop” concept. Simulations were performed using ANSYS fluent and the results the capability of the concept to produce a sufficient amount of shear to significantly reduce the dynamic viscosity between injection molding cycles. To validate the concept experimentally, a hot runner mold was modified to retrofit the Rheo drop technology. The experimental results show that this technology is able to enhance the quality of molded parts and prevent incomplete filling defects.