The sensitivity of the behavior of water penetrating polypropylene matrix composites on short‐shot process parameters

Abstract Water‐assisted injection molding of polymer matrix composites effectively combines the advantages of both the materials and technique and is now emerging into the limelight. Pipe hole length and pipe thickness are important indices of the products of this process and can be used to describe the water penetration behavior. In this paper, the sensitivity of water penetration behavior on the main process parameters was studied. The study shows that the water penetration behavior is most sensitive to the melt injection volume percent. For example, as the melt injection volume percent is increased, the pipe hole length is decreased from 231 mm to 116 mm, and its fluctuation is increased from 0.9% to 7.1%. The pipe thickness shows a significant change in the rear parts of the main cavity, followed by the water pressure and delay time, and, finally, the melt temperature. Furthermore, the pipe thickness in the middle of the main cavity is found to be the most sensitive to these process parameters. The above results provide certain guidance for adjusting the process parameters of the short‐shot method.