Safran Cabin, a leading supplier of cabin interiors, and materials supplier Victrex have worked together to qualify thermoplastic composite parts on aircraft. A flexible platform is being designed to cut planning and time-to-market of multiple brackets, with the first being a hybrid overmolded aircraft cabin bracket made of Victrex AE 250 carbon fiber PAEK composite and Victrex PEEK polymer. Victrex, provided the material, process and tooling expertise required to realize versatile design features while meeting key performance parameters. Safran Cabin provided critical expertise in design and manufacturing to ensure applicability in aerospace service and certification environments.

"We need to respond to many demands for aircraft brackets and similar structural parts, with each case having many loading, constraint, and exposure conditions," said Tyler Smithson, R&T Engineer at Safran Cabin. "The key to success is to develop a flexible composite platform that can be used for multiple projects, lowering our part count and design complexity, cutting time-to-market, speeding time-to-revenue."

Victrex and Safran Cabin utilized an innovative technique where Victrex AE 250 thermoplastic composite is overmolded with Victrex PEEK high performance polymer. This hybrid overmolding technique is a scalable, repeatable technology with potential to help commercial aerospace customers face the challenges of needing much lower scrap rates, faster cycle times, part consolidation, and reduction in the number of secondary operations. Stringent testing and qualification work have indicated that structural aircraft parts produced from Victrex AE 250 via hybrid overmolding can withstand high levels of mechanical stress.

With Safran Cabin, the design process focused on defining parts and molds adaptable for multiple brackets, with the goal of achieving a family of designs compatible with the same mold. This involved establishing a cost and weight advantage while considering the flexibility of the platform to be used in various applications.

Following the initial design phase, mold-filling and structural simulation methods were combined with various physical testing techniques to identify and mitigate new technology failure modes and to streamline injection molding manufacturing and cost constraints. Critical characterizations were refined, and a productive, repeatable design process has been developed.

"At Victrex we are proud of our track record in introducing 'disruptive' technological approaches in the sectors that we serve, using our know-how in the processing and performance of PAEK materials to accelerate the commercialization process," commented Tim Herr, Director, Aerospace at Victrex. "Hybrid overmolding and Victrex AE 250 composites are certainly within this category but this is just the beginning. We continue to test our composites offering, with support from our customers and partners in order to demonstrate the full potential of these materials.”

The initial prototype brackets were produced at Tri-Mack Plastics Manufacturing Corporation. Compared to the original aluminum part, the prototype composites contribute to a 20% cost saving; 50% weight reduction; and a 5x better buy-to-fly ratio. The buy-to-fly ratio is the weight ratio between the raw material used for a component and the weight of the component itself.