Conventional adhesive bonding uses thermosetting adhesives. Typically, the adherents can be separated only by destructive means, usually incurring damage to one or both of the joined substrates. ORNL has demonstrated the means to join substrates with thermoplastic adhesives that can be loosened by melting the thermoplastic. This melting is accomplished via microwave heating that preferentially heats the adhesive region with little to no warming of the substrates. This method is possible using a coordinated selection of appropriate susceptors (coupling enhancers) that are embedded in the adhesive along with processing frequency tuned to the materials and joint configuration. Moreover, researchers have determined the technique permits multiple cycles of binding and debonding, frequently without needing to add more adhesive.
Techniques have been demonstrated for relatively large bonded areas of fiberglass composites and certain adhesive/substrate combinations, although the approach may be more generally applicable.
ORNL researchers are not aware of comparable technologies for intentionally fully bonding then debonding and rebonding structural joints without risk of damage.
The technology is available for further development, demonstration, and application under a variety of customer agreements.
Dr. Felix Paulauskas, Senior Carbon Fiber Researcher, email@example.com, 865-576-3785