Click Bond bonded nut plate stand-off.
Click Bond bonded nut plate stand-off.

The stand-offs, which consist of a nut plate attached to a stand-off bracket, are used to provide support for the cargo doors as attachment points for the cargo door liner.

VICTREX polyether ether ketone (PEEK) polymer replaced a glass and epoxy composite used on previous stand-offs.

"Injection moulding the part with VICTREX PEEK polymer is a good alternative to glass and epoxy composite, especially when higher volumes dictate a production method with a much faster cycle time and lower part cost," explains Mark Egeberg, Pacific Regional Manager of Click Bond, a supplier of adhesive-bonded fastener systems.

"The polymer provides the necessary properties required for structural attachments in aerospace applications, including superior bond strength, high strength and stiffness, excellent flammability performance, and resistance to hydraulic fluid."

In addition, the polymer can be injection moulded in thin walls and allows for excellent wet-out of high fibre content.

The use of adhesive to bond mounting hardware to the structure eliminates the need to drill and dress holes, and install rivets.

"Adhesive bonding is faster and also saves significant time and money, should an attachment require relocation and rework is necessary because no holes are drilled," confirms Egeberg.

As well as reducing part count, eliminating rivet holes reduces fatigue and corrosion potential.

Click Bond uses a self-fixturing process to maintain an accurate position on the substrate during bonding with a permanent structural adhesive.

"Our 'fixture-in-place' process allows the adhesive to cure with constant pressure and consistent bondline thickness," says Egeberg. "The self-fixturing parts eliminate the need for special tools, clamps and drills, thus speeding up the process of installing attachment bracket hardware."