Additively manufactured resin transfer molding (RTM) plastic tooling for producing composite T-joint structures

Abstract Resin transfer molding (RTM) is a manufacturing process used to produce high-quality composite parts that offer exceptionally high strength-to-weight ratios, superb stiffness, and excellent resistance to corrosion and fatigue. These composites are typically composed of carbon or glass fibers infused with a liquid thermosetting resin that hardens during a high-temperature cure cycle. A matched metal mold is usually required to produce RTM products. The mold cavity is shaped to the desired geometry of the finished composite part, and channels or gates allow the resin to flow into it. In cavity mold design, there are numerous challenges related to resin injection gates, vents, and the direction of resin flow. The challenges include considerations for filling time and the flow dynamics of the materials. These issues often require costly iterations to perfect the cavity design for a given part. This study focuses on the use of additive manufacturing (AM) in developing and fabricating plastic prototype molds that can be used to produce a limited number of finished composite parts, such as T-joints. These joints usually suffer from weaknesses in the deltoid regions, where the web and flanges meet. Accordingly, the influence of using different deltoid filler materials on the mechanical performance of T-joints was investigated experimentally under tensile loading to ensure the reliability and durability of the fabricated parts. The main goal is to present innovative and economical approaches, allowing for rapid and low-cost iteration of composite designs and solving the problem of deltoid regions using appropriate filling materials.