Böllhoff and DELO have combined expertise and proven joining technologies for the aerospace industry, the ONSERT fastening element from Böllhoff and the light-curing high-performance adhesive DELO PHOTOBOND FB4151 from DELO, to enable lightweight, material-friendly and flame-retardant compliant fastenings in aircraft interiors. The result is an efficient alternative to conventional screw or riveted joints that is ideal for applications such as cable holders on lightweight components. Additionally, short curing times and easy automation support highly scalable manufacturing processes in the aerospace industry.

The Adhesive

The DELO PHOTOBOND FB4151 adhesive is a modified UV- and light-curing acrylate that was specifically developed for use in aircraft interiors. It cures within a few seconds and achieves high strengths of around 20 MPa on various aerospace-typical plastics and metals while maintaining high flexibility with around 80% elongation at break.

The recommended operating temperature range of the adhesive extends from −40 °C to +120 °C. With its fire and smoke behavior, it meets aerospace requirements according to FAR Part 25 § Section 25.853 (a)(1)(i) Amdt. 15/Amdt. 25-116 and ABD0031. In addition, the adhesive has low outgassing, is solvent-free, and complies with Directive 2015/863/EU (RoHS).

The Fastening Element

The ONSERT process from Böllhoff combines bonding and mechanical fastening in one technology. Transparent plastic elements are applied directly to lightweight materials using the light-curing adhesive — without drilling or local material weakening. This protects composite materials and allows for great freedom of design. After curing, functional elements such as cable holders can be easily clipped on. With curing times of around eight seconds and the possibility of automated processing, the solution is ideally suited for series production.

"The combination of the ONSERT fastening element from Böllhoff and the DELO adhesive creates a powerful joining technology for aircraft interiors – lightweight, process-reliable and ideal for series production," said Franz Drüke, product manager at Böllhoff.

"Our light-curing adhesives have been successfully established in the automotive industry for years. Now they also enable efficient manufacturing processes with short cycle times and great freedom of design in the aerospace industry," explained Sebastian Stasch, product manager industrial solutions at DELO.

The technology has already demonstrated its potential in initial aircraft seat development projects, for example in the fastening of cable routing in business class seats from Recaro. Further applications for cabin equipment and other lightweight structures are in the qualification phase.

Learn more about DELO at delo-adhesives.com.