Experimental development and evaluation of a resin injection system for pultrusion

Wet-out, the exposure of dry reinforcement to resin in order to coat the reinforcement with resin, is one of the process factors that must be controlled in order to produce quality composites. Both open-bath and closed, resin injection wet-out methods can be used with the pultrusion process. Although various resin injection techniques are used by commercial pultruders, the technical details of these techniques are not available in the open literature. Because of the lack of information available to the majority of the industry, the intent of this paper is to present basic information about resin injection techniques that can be used in the development of resin injection pultrusion systems. Experimental results and observations presented for this study demonstrate the importance of factors such as injection chamber design, injection pressure, type of fiber, and the elimination of voids for resin injection pultrusion systems.