Crash-resistant adhesives and reinforcing elements
The challenges in vehicle construction are becoming greater: lightweight construction, integration of heavy batteries in electric vehicles, compliance with more stringent crash safety requirements, cost pressure, flexibility and shorter development times are aspects that are often difficult to reconcile with each other Adhesives, foams and plastic parts that only exhibit their final properties after curing in the E-coat oven are being used more frequently.
Innovative HSB technology, which combines crash-resistant adhesives with reinforcing elements, creates entirely new possibilities for body shell design. Along with improved deformation and intrusion characteristics in the event of an accident, this usually results in greater body integrity
The Sika Concept: precise reinforcement
In the SikaReinforcer® technology introduced 15 years ago, reinforcement elements made from plastic (SikaStructure®) are adhesively bonded to surrounding sheet metal parts using structural foam. Using adhesives that can withstand, crashes instead of structural foam enables further massive improvement in the performance of the reinforced structure.
Crumpling of profiles due to high local forces is prevented, which allows component deformation to be reduced significantly. The crash resistance of the structural adhesives ensures a reliable transfer of loads in tensile and shear to the body shell structure.
With HSB, the adhesive is applied in a thicker layer than with conventional steel-to-steel structural bonding (see Figure 1). This requires materials with suitable strength and adhesion properties. Special adhesives have been developed for this new bonding technology. Test methods and processes for this application have been defined in cooperation with vehicle manufacturers.
For example, the process capability required in the manufacturing facility, adhesion characteristics with various substrates and mechanical properties have been determined by an extensive set of validation tests (see Figure 2).
Deformation is dramatically reduced by HSB: For example, the process capability required in the manufacturing facility, adhesion characteristics with various substrates and mechanical properties have been determined by an extensive set of tests (see Figure 1).