Partial Frame Process (PFP) is one of the injection molding techniques, in which the void core is generated by imposing the low pressure air into the molded part just after the resin is completely filled, afterwhich the void grows as it compensates the volume shrinkage of resin. This technique can help to cure the deformation problems in common injection molding processes such as sink mark and warpage, with less pressure and more benefits. In spite of its advantages, systematic study is lacking and not enough is known about this process. Recently, we have modeled the void growth in PFP, and could explain the experimental data quite successfully in spit of some assumptions. In this study, experimental approach was taken in order to obtain more systematic understanding about the mechanism of void growth in PFP. As there are many factors affecting the process, the design of experimentals was adopted. The contributions of each factor was cleared, and it was found that the air pressure plays key roles in the generation and growth of void among the many factors. Together with the results of modeling, this study is expected to help our understanding of this new process as well as the mold design and the determination of the operating conditions