The two suppliers have teamed up to provide an innovative new fastening process, which combines the advantages of mechanical fastening with those of bonding. Designed for use where a strong, secure mechanical threaded fastening is required in lightweight applications, the innovation has been named ONSERT.
This new hybrid fastener is said to be an especially practical solution for design teams working with plastic, composite or carbon fibre materials that must either be attached to something or have items attached to the panels themselves. The ONSERT process involves bonding a stud with either an external or internal thread direct onto panel, and this can then be used either to join various panels together or simply to attach additional items onto the panel itself.
Using either DELO’s Photobond or Dualbond light cured adhesives, the Bollhoff Onsert threaded fasteners can be placed onto almost any material surface and flash cured into place in as little as 4 seconds: full mechanical load capacity is achieved immediately after irradiation and, due to an adjusted lamp geometry, optimal curing is guaranteed in less than 5 seconds. This provides the mounting of a stud of up to M6 in size to offer real choices to design engineers, in particular those facing the challenges of achieving lightweight structures that are resilient enough to withstand many years of service. Further advantages include the ability to remove items or replace panels at will, as required, with disassembly able to take place limitless times throughout the lifetime of the product without degradation of fastening performance.
Further, because the Onsert fastening method is non-invasive, panels and parts can be mounted with integrity and security, without weakening the host material by interfering with its ‘grain’. As it is applied only to one surface, use of the Onsert method of fastening leaves a ‘clean’ side of a panel or material, which is also seen as an advantage in many applications, particularly those where an aesthetically pleasing finished product is required.
In addition to panels and sheets made of plastics, composites or carbon fibre, ONSERT can also be used where metals, aluminium or alloys are the host material onto which the fastener is to be attached. This has allowed design teams to explore new opportunities outside of joining methods, such as brazing or welding, providing an alternative which is not only cost effective, but also does away with the considerable energy usage and necessary associated processes.
Not least amongst these is a cleaner working environment on the shop floor where assembly takes place, coupled with a speedier flow of work. It also offers design teams the advantage of zero disruption to the surface of the materials being joined.
Two recent and very different examples of applications in which Onsert has been specified are in offshore wind farms and on domestic appliances. In the former, Onserts were placed onto corrosion-resistant panels to facilitate the mounting of associated equipment in transformer cells of wind turbines and, in the latter, they proved to be an ideal solution for the mountings required on the glass panels used in cooker extraction hoods.
