Pull Speed Influence on Fiber Compaction and Wetout in Tapered Resin Injection Pultrusion Manufacturing

In the resin injection pultrusion process (RIP), liquid resin is injected into the tapered injection chamber through the injection slots to completely wetout continuously pulled fibers. As the resin penetrates through the fibers, the resin also pushes the fibers away from the wall towards the centerline, causing compaction of the fiber reinforcements. The fibers are squeezed together due to compaction, making resin penetration more difficult; thus at low resin injection pressures, the resin cannot effectively penetrate through the fibers to achieve complete wetout. However, if the resin injection pressure is too high, the fibers are squeezed together to such an extent that even greater injection pressure is necessary to wetout the compacted fibers. The design of the injection chamber significantly affects the minimum injection pressure required to wetout the fiber reinforcements. A tapered injection chamber is considered such that wetout occurs at lower injection pressures due to the taper angle of the injection chamber. In this study, the effect of fiber pull speed on the fiber reinforcement compaction and complete fiber wetout for a tapered injection chamber is investigated.