Injection Bonding with DuPont
DuPont™ has extended its composite bonding technology for carbon-fibre by adding an innovative injection bonding technique for BETAFORCE™ composite bonding adhesives.
Injection bonding is a further example of the customizing capabilities of BETAFORCE to address specific customer requirements for production, such as open times and cycle times, without affecting mechanical properties. By adjusting these parameters individually, DuPont helps customers improve their assembly process efficiencies. Furthermore, this enables the wider application of carbon-fibre parts in mixed-material assembly and thus supports manufacturers’ lightweight strategies.
Where Can DuPont’s Injection Bonding Be Used?
Injection bonding can be used as a special process to composite bonding in parts to metal in side-frame applications along the roof. Here, the carbon-fibre part is used as an inlay in a metal housing running along the A-pillar into the roof and down the D-pillar. This ensures the stability of the passenger compartment in the case of a side-pole impact or rollover, as well as increasing vehicle torsional stiffness while improving subsequent ride-handling and NVH at the lowest mass.
The challenge of integrating such long carbon-fibre composite parts is the management of the differential Coefficient of Linear Thermal Expansion (CLTE) along the assembly as well as during the operative life of the vehicle. BETAFORCE technology helps address this challenge, as has been demonstrated in the BMW Group, with the BMW 7 series.
BETAFORCE™ Composite Bonding Adhesives
Based on a two-component polyurethane structural adhesive technology, BETAFORCE is characterised by a high elongation factor and outstanding modulus. While the high modulus provides the needed stiffness, the elongation factor enables a high level of energy absorption and flexibility to manage differential CLTE.
To achieve the best composite bonding, the adhesive is injected by a robot and surrounds the carbon-fibre for a durable bond of different substrate components. Additionally, BETAFORCE provides superb adhesion to multi-material substrates, such as carbon-fibre or coated metal, enabling advanced lightweight solutions for automotive manufacturers such as BMW Group.
Materials joined by BETAFORCE include carbon-fibre with coated steel and with coated aluminium. Application areas include roofing, complete carbon-fibre compartments or hang-on parts, such as doors.
DuPont BETAFORCE solutions have since been successfully used for enabling super-fast charging of electric vehicles, electric-hybrid vehicle composite bonding and bonding vehicle battery packs. In addition, BETAFORCE has won an Edison award for its achievements in the automotive industry.
