New high performance adhesive uniquely offers fire, smoke and toxicity compliance to simplify aircraft interior manufacturing processes

Diversified technology company 3M has developed what it believes to be the world's first two part structural epoxy adhesive to meet aerospace fire smoke and toxicity (FST) standards (when tested standalone) without the need for additional treatments or surface coatings. The adhesive meets the requirements laid down by FAR 25.853 (a) flaming mode, JAR 25.853 (a) flaming mode and ABD 0031 & AITM 2.0002A as defined by the US flight authorities, European flight authorities and Airbus respectively.

Scotch-Weld adhesive 7246-2 B/A FST is set to substantially simplify many aircraft interior manufacturing tasks by allowing builders to complete assembly and FST compatibility operations in a single step. The versatile product will also replace several different types of conventional adhesive, simplifying stocking requirements and improving productivity.

Scotch-Weld adhesive 7246-2 B/A FST is a room-temperature curing structural two-part epoxy paste adhesive system. Its thixotropic, non-sag formulation makes it easy to apply without dripping or deformation. The product is ideal for a host of aerospace interior tasks, such as the corner splicing of honeycomb panels, insert bonding and the bonding of tubular ducting.

Scotch-Weld adhesive 7246-2 B/A FST allows completed assemblies to meet FST requirements without additional surface treatment. The product is light tan in colour to match conventional honeycomb skin materials, and can be over painted using the same surface coatings as the panels without leaving unsightly shadows.

"Our aerospace customers need to produce assemblies that meet extremely demanding FST standards. Up until now, those requirements have precluded them from taking advantage of modern easy-to-use structural epoxy adhesives where the adhesive will form part of the outer surface of the finished product," explains John Lester, Key Account Manager at 3M. "Because this new product meets FST requirements itself, it will dramatically simplify a host of edge finishing, gap filling and insert bonding operations. We expect Scotch-Weld adhesive 7246-2 B/A FST to become the standard choice for the final assembly of many aircraft interior structures."

Scotch-Weld adhesive7246-2 B/A FST has a typical worklife of 45 minutes  and reaches handling strength in three to four hours under the same conditions. The product is available in an EPX duo-pack cartridge for simple, accurate application or in bulk containers for hand mixing or use with automated mixing equipment.

Compatible with most common aerospace interior substrates including aluminium honeycomb, polycarbonate, glass/phenolic panels, polyetherimide and polyphenylsulfone, Scotch-Weld adhesive7246-2 B/A FST is resistant to damage by water, salt spray, jet fuel and mineral oils.

3M, Scotch-Weld and EPX are trademarks of 3M Company.