An assessment of additive manufactured molds for hand-laid fiber reinforced composites

Composite materials are currently in high demand because of their unique properties, such as high stiffness, light weight, and distinctive appearance. A composite material composed of fibers and a resin can be manufactured through a variety of methods. One such method typically used for low production volume and custom applications is the hand layup method, which involves manually combining fibers and resin on a mold surface. For large quantity manufacturing and production of composites, molds are typically made out of a highly durable material like aluminum or steel. The initial investment of the mold is recovered through the manufacturing of numerous parts. However, in low volume and one-off productions, molds are typically handmade by a composite technician, which increases the cost to manufacture a part. The objective of this project was to use large area additive manufacturing, commonly known as 3-D printing, to create molds for these small scale production runs and assess the ability to use them for hand layup composites. After printing, some molds were treated with various surface coatings, and others were machined by a CNC mill. The finished molds were used for hand laying of fiberglass parts in order to assess the durability and resulting surface quality. It was found that printed molds could be an effective approach for limited production runs (4-5) of fiber reinforced composite parts, depending upon the mold shape, surface finish, and coating composition.