DELO says that ONSERT® technology, based on stud welding, combines bonding and screwing by equipping fastening elements, such as threaded metal bolts, with a transparent plastic base and bonding it to fibre composite materials. The threaded rod of the ONSERT can be screwed and – when necessary – removed again.
With ONSERT, composites, thin sheet metals, plastics and other materials are equipped with a multi-purpose connection element. Composite materials, such as CFRP and GFRP, take established joining technologies including welding, screwing and riveting to their limits.
The special feature of the ONSERT technique is its speed as the adhesive is cured within approximately 4 seconds using an LED lamp. It is also possible to fully automate this process and the bonded connection can be loaded immediately. Bonded bolts with a base diameter of 25mm achieve a pull-off strength up to 2,000N on CFRP. When applying higher forces, a predetermined breaking point in the base ensures that the laminate of the composite material remains intact and no fibres are torn out. Nevertheless, the ONSERT is robust as shown by salt spray and VDA climate tests.
In addition, ONSERT excels due to its flexibility in design and production. First, the structural shape can be defined by the user to a great extent, particularly in terms of rod length and base diameter. Second, they provide much freedom in production as bonded bolts can be attached to the raw body and prior to final assembly of lacquered elements.
Böllhoff and DELO have tested this technology in a series of pilot projects including fixing of cables, claddings and other components of the BMW i3.
ONSERTs are suitable for a broad variety of applications including cable harnesses, control units, sensor retainers, brake lines, claddings or exterior attachment components, cover plates, insulating materials, floor panels in airplanes, and white goods.
Having spent a decade in the fastener industry experiencing every facet – from steel mills, fastener manufacturers, wholesalers, distributors, as well as machinery builders and plating + coating companies, Claire has developed an in-depth knowledge of all things fasteners.
Alongside visiting numerous companies, exhibitions and conferences around the world, Claire has also interviewed high profile figures – focusing on key topics impacting the sector and making sure readers stay up to date with the latest developments within the industry.