Alternative Heating Technology for Thermoplastic Composites and Adhesive Bond Processing

Production Products will develop microwave/RF heating or other directed energy heating techniques for the processing of thermoplastic composites and adhesive bonds with the support of our subcontractor Southern Research Institute and our aerospace mentor McDonnell Douglas Aerospace. Use of directed energy to heat only the polymer in the composite or the bond line eliminates the need for expensive, high-temperature bagging materials, sealants, tooling, and equipment and also allows thermoplastic bonding/repair with low temperature substrates, such as epoxy matrix composites or aluminum. The thermoplastic bond could also be reheated and removed providing a bonded joint with the removable advantages of mechanic fasteners. A wide variety of engineering thermoplastics exist that are excellent adhesives and matrix resins for structural composites. These materials have high strain-to-failure, toughness/damage tolerance, damping, low-moisture uptake, low dielectric properties, excellent fire and smoke characteristics, and wear resistance. In Phase I, Production Products will demonstrate the feasibility and physics understanding of directed energy heating for thermoplastic composite and adhesive bond processing. We will select/develop the most promising alternate heating technologies, combine them with low cost tooling concepts and fabrication methods and demonstrate low cost application of thermoplastic composites and thermoplastic bonding to Navy aircraft structures fabrication and repair.