RAPID CURE HONEYCOMB SANDWICH COMPOSITE REPAIR

With the increased reliance on enhanced composite material system capabilities to meet the operational demands of the 21st century warfighter, the Navy has a critical operational requirement for a lightweight honeycomb core filler for repairs. The current repair and maintenance approach requires a short, room-temperature cure in order to maximize the life of these high-performance composite components and structures. There are two general repair approaches for sandwich structures: core fill and replacement honeycomb. For large repairs, replacing the honeycomb is currently required due to the weight and structural performance attributes associated with state-of-the-art (SOTA) materials. As such, a novel, light-weight, fast-curing filler material, dubbed HexHeal Pro, is being developed with enhanced mechanical properties to facilitate larger potting repairs that would eliminate the need to replace the honeycomb. The material formulation features fire retardancy not currently characteristic of comparable legacy systems, and minimizes downtime by curing swiftly, enabling faster repairs and reduced operational disruptions: 1 hour time to sand (finishing operation) versus 8 hours for the incumbent, legacy material. HexHeal Pro also cures across a broad temperature range, which means assets can be reliably used for repairs in diverse environmental conditions and operational settings including exposure to freezing temperatures (0°C, 32°F). These improvements enable a 70% reduction in repair time and 50% increase in the diameter of repairs. Streamlining larger honeycomb repairs has the potential to return a significant cost-savings to the Navy and also positively impacting the operating tempo (OPTEMPO) of the associated platforms.