Resin injection pultrusion is an efficient and highly automated continuous process for high-quality, low-cost, high-volume manufacturing of composites. The main objective of this study is to explore the "attached-die configuration" and "detached-die configuration" for improving the resin injection pultrusion process. In this work the impact of pull speed on complete wet out of the reinforced fiber is investigated for attached-die and detached-die resin injection pultrusion with various chamber length considerations. A 3-D finite volume technique was applied to simulate the liquid resin flow through the fiber reinforcement in the injection pultrusion process. This work explores the resin injection pressure needed to achieve complete wet out and the corresponding maximum pressure inside the resin injection chamber so as to improve injection chamber design to keep the pressure within the injection chamber within reasonable constraints for different pull speeds.

The objective of the present study is to improve the pultrusion process by improving the reinforcement wetout, and thus, the quality of the pultruded part in the resin injection pultrusion process. The emphasis here is on one of the processing parameters (pull speed/line speed) with a slot injection tapered chamber by varying the length of the injection chamber. Investigated is the impact of tapering of the walls of the injection chamber on the minimum injection pressure necessary to achieve complete wetout via varying the length of the tapered injection chamber and also the pull speed. This work presents the injection chamber exit pressure, since this is important for chamber design with respect to personnel safety and die/chamber damage.

Resin Injection Pultrusion (RIP) is an automated, continuous process and is one of the most cost-effective methods for manufacturing composite materials with constant cross sections (such as rod stock, beams, channels and tubing). In the present work, a 3-D finite volume technique was developed to advance the liquid resin flow front through the fibre reinforcement in the injection pultrusion process. The objective of this study was to improve fibre reinforcement wet-out and thus the quality of the pultruded part in an injection pultrusion process. The complete wet-out of the dry reinforcement by the liquid resin depends on various design and process parameters. The design parameters explored in this study were the aspect ratio of the final composite, injection slot width, injection slot location from inlet of injection chamber, and location of the multiple injection ports. The numerical model simulates the flow of polyester resin through glass rovings and predicts the impact of the design (geometric) parameters on wet-out, resin pressure field, and resin velocity field. The location of the liquid resin flow front has been predicted for an injection slot, as well as for five discrete injection ports.

In resin injection pultrusion, the liquid resin is injected through the injection slots into the fiber reinforcement; the liquid resin penetrates through the fibers as well as pushes the fibers towards the centerplane causing fiber compaction. The compacted fibers are more difficult to penetrate, thus higher resin injection pressure becomes necessary to achieve complete reinforcement wetout. Lower injection pressures below a certain range (depending upon the fiber volume fraction and resin viscosity) cannot effectively penetrate through the fiber bed and thus cannot achieve complete wetout. Also, if the degree of compaction is very high the fibers might become essentially impenetrable. The more viscous the resin is, the harder it is to penetrate through the fibers and vice versa. The effect of resin viscosity on complete wetout achievement with reference to fiber-reinforcement compaction is presented in this study.

Manufacturing of composite materials using resin injection pultrusion is presently a cost-effective method of producing composites; however, there is still a potential for significant improvements in the productivity of this approach for high-speed production. Complete wetout of the dry fiber reinforcement by the liquid resin at high pull speeds is essential for improving the throughput of the pultrusion process. Complete fiber reinforcement wetout depends strongly on axial placement of the injection ports/slots and the geometry of the injection chamber (taper of the walls of injection chamber and final part thickness). Geometric parameters modeled in this study were multiple injection ports and their axial location within the injection chamber and thickness of the final pultruded part; investigations of these geometric parameters are original contributions of the work. In this study, the finite volume numerical technique was employed to model the flow of polyester resin through the glass fiber reinforcement. Results depict the impact of varying the thickness of the pultruded part and the use of multiple injection ports on the minimum injection pressure necessary to achieve complete fiber matrix wetout and on the resin pressure at the injection chamber exit for the slot injection and for the discrete port injection configurations. This model is a useful guide for improving the efficiency and productivity of the resin injection pultrusion process for an attached injection chamber configuration with tapered walls.