Online measurement of rheological properties of polypropylene based on an injection molding machine to simulate the injection-molding process

For accurate prediction of the service performance and service life of polymers and the optimization of processing parameters, novel test equipment based on an injection molding machine was developed to measure the rheological properties under certain processing conditions. The rheological properties of a semicrystal-line polymer, polypropylene, were measured using this novel mold under normal processing conditions, and the data were correlated by the Cross-WLF viscosity model. The differences in the rheological properties between online group and other techniques were observed. Numerical simulations of injection-molding processes were carried out by Mold-flow software with online and offline data of rheological properties for polypropylene. Improvements in the accurate prediction of warpage and shrinkage performance with input of online rheological data are presented compared to the offline ones.