Multi-layer thermoplastic spray coating system for high performance sealing on airplanes

An assembly comprising;

• a first substrate;
• a second substrate joined to the first substrate;
• a multi-layer sealant located on at least one of the first substrate and the second substrate, said multi-layer sealant comprising:
• a first thermoplastic polymer layer applied to a substrate, said first thermoplastic polymer layer comprising a first thermoplastic polymer, said first thermoplastic polymer comprising at least one:
• of a thermoplastic co-polyester, a co-polymer of vinylidene fluoride and hexafluoropropylene, a thermoplastic polyurethane, a thermoplastic vulcanizate, a thermoplastic polyolefin elastomer, a styrene block co-polymer, a fluoroelastomer, and combinations thereof;
• a second thermoplastic polymer layer deposited onto said first thermoplastic polymer layer, said second thermoplastic polymer layer comprising at least one of:
• a polyether ether ketone, a polyether ketone ketone, a polyamide, a polysulfone, a polyphenylsulfone, a polyetheramide, and combinations thereof;
• wherein the first thermoplastic polymer is different than the second thermoplastic polymer;
• wherein the first substrate and the second substrate are configured to be joined together to form an interface, said interface located between the first substrate and the second substrate;
• wherein the interface comprises at least one of a fillet seal and an edge seal;
• and
• wherein the first thermoplastic polymer layer applied to the at least one of the first substrate and the second substrate comprises an adhesion value ranging from about 10 lbs/in to about 30 lbs/in wide area in 90° peel test according to ASTM D6862-11(2016).