Polyurea Bi-Layer Coating for Self-Sealing Fuel Tanks

Self-sealing fuel tanks play an important role in protecting equipment and personnel by minimizing secondary threats from a ballistic penetration of the fuel tank. If a fuel tank is pierced by a projectile, the self-sealing bladder or coating uses a combination of elastomeric recovery in addition to fuel absorption and swelling to close the penetration and quickly stop a fuel leak. In this manner, the self sealing function can reduce the occurrence of fire or explosion and extend the mission. In order to provide the safety of self-sealing fuel tanks in a reliable, light-weight, low-cost solution, Luna Innovations is teaming with the Southwest Research Institute and prime aerospace contractors to develop a polyurea bi-layer coating system. The system will be spray applied to the exterior of a fuel tank in two layers. The inner layer is a novel, fuel absorbing elastomer which serves the dual roles of elastomerically shrinking the entrance wound, and swelling with fuel to close off any remaining opening. The external layer is fuel resistant and provides excellent elastomeric recovery to a penetration, and protection of the inner layer.