Oven Vacuum Bag (OVB) prepreg fabrication is an evolving process that can result in low cost, high quality composite structures. Compared to vacuum assisted resin transfer molding (VARTM), material costs are higher but man-hour requirements are lower. Breakthrough innovations in prepreg materials for non-autoclave fabrication have resulted in the ability to fabricate low void content laminates using only a vacuum bag at 160 °F for consolidation. One of the advantages with OVB prepreg is the quality that can be attained by male molding on inexpensive NC-machined foam plugs. Male-molded parts are sometimes preferred since they reduce tooling and fit-up costs required to meet tight tolerances. Although male-molded parts typically have poor surface quality on the vacuum bag side, the characteristics of OVB prepreg can be used to improve this condition significantly. Since consolidation does not require resin flow through the surface, polished caul tools can be used directly against the prepreg. An evolving fabrication approach is described herein in which male-molded OVB prepreg is used in conjunction with caul tooling and surfacing films to produce a part with two molded surfaces.
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