Effect of Fiber Volume Fraction in Fiber Reinforcement Compaction in Resin Injection Pultrusion Process
In the resin injection pultrusion process (RIP), the liquid resin is injected into the continuously pulled fibers through the injection slots to cause complete wetout of the fibers. As the resin penetrates through the fibers, the resin also pushes the fibers away from the wall causing compaction of the fiber reinforcements. When the fibers are squeezed together due to compaction, the resin penetration becomes more difficult; thus a resin injection pressure below a certain pressure cannot effectively penetrate through the fibers and achieve complete wetout. However, if the resin injection pressure is too high, the fibers are squeezed together to such an extent that the fiber becomes essentially impenetrable by the liquid resin. The harder it is to penetrate through the fibers, greater is the tendency of the fibers to be pushed away from the wall and cause compaction and affect wetout. In this study, the effect of fiber volume fraction on the fiber reinforcement compaction and the complete wetout is presented.