Optimization of Injection Molding Parameters for Isotactic Polypropylene using Box-Behnken Design: An Empirical Analysis

This research uses statistical methods to identify the most influential parameters of the injection molding process, aiming to enhance the mechanical properties of isotactic polypropylene (iPP). The Box-Behnken design (BBD) was implemented to examine four key factors: Melting temperature, Injection pressure, Holding pressure, and Mold temperature. Minitab 21 software was employed for designing the experiment and conducting statistical analysis. Findings revealed that injection and holding pressure notably influenced the ultimate tensile strength. Moreover, melting temperature and mold temperature had a significant effect on the flexural strength. However, the parameters of the injection process did not display a substantial impact on the strain at yield and impact resistance. The microstructure of iPP specimens was analyzed using POM, and DSC. The investigation indicated a decrease in the thickness of the tensile specimens‘ skin layer with the increment of melting and mold temperatures.