Adhesive Bonding compared with other Fastening Techniques

Adhesive bonding is a proven and well-established fastening technique that complements the existing range of traditional fasteners throughout the manufacturing industry. The first use of elastic adhesives to bond components and assemblies in the manufacture of vehicles dates to the early 1980s.

Whether elastic or rigid, the adhesive bonding process differs fundamentally from the mechanical joining techniques. In contrast to rigid ones, flexible adhesives can deform during load transmission and make structural adhesives a widespread fastening technique in the industry.

(+) Lightweight Design: Adhesive bonding has enabled the development of mixed material designs. Additionally, it allows better use of specific material properties by better load transfer and reducing peak stress.

(+) No thermal distortion: Thermal distortion and deformation are common issues related to welding. Such damages need to be corrected with sanding and polishing steps. Additionally, some materials like ultra-high-strength steel grades lose their strength when exposed to heat.

(+) Better Stress Distribution: Adhesive bonding results in a more even distribution of stresses and helps maximize a component's service life or reduce the material thickness. Compared with rigid structural adhesive bonded structures that distribute stress along the bond line, elastic adhesives allow a stress distribution over the entire bonded area.

(+) One Step - Sealing and Bonding: When joining parts with adhesives, they act as a sealant in the same step. It is proven that adhesive bonding shows better protection against crevice corrosion and galvanic corrosion than other fastening techniques.

(-) Strength Development: Unlike mechanical joints, adhesive bonds do not immediately reach their maximum or ultimate strength. In many cases, however, assemblies can be handled and passed on to the following processing stage before attaining their final strength levels.

Integration of Adhesive Bonding into Vehicle Design and Production

Even though structural adhesive bonding is well established within the industry, there are still many use cases that could benefit from it. While working at the headquarters of an adhesive manufacturer, I am involved in many projects throughout the global industry. Taking more significant steps is more challenging, especially in conservative markets. However, substituting a traditional fastening technique with adhesive bonding leads to a considerable value, and we seldom see customers return to the former process.?

Designing for Adhesives

However, in such projects, we often experience that design?engineers struggle to design for adhesives. In a classical curriculum of an engineer, universities are still going much more profound with traditional fastening techniques and welding than with adhesive bonding. That's why Sika offers comprehensive material data and supports engineers in identifying an appropriate calculation model.

Sika is partnering with calcbond from AR Engineers to provide a simple toolbox for engineers to assess the feasibility and design joints for adhesive bonding.

Learn more about the calcbond app from AR Engineers

Integration into Serial Production

Additionally, once the gains of using adhesives for a particular application have been understood and the design changed, production people most familiar with mechanical fastening tend to request they can further process parts immediately. In most cases, this is not required. While applying adhesives and joining the parts is typically faster, adhesives need time to develop enough strength to move or further process the joined components. I want to point out that if people consider that no labor is required during this time, the savings are still there. With enough buffer in the assembly process, using adhesives is easy and reliable.

Sika representatives and technical service experts provide tailored solutions and recommendations for optimal fit into your production. Learn more by joining our event on June 14 and 15, 2022

With our solutions and knowledge from the automotive industry, Sika has the competence to guide you on your journey to adhesive bonding, whether in the weld shop, the assembly line, or the aftersales.?

Learn about Sika solutions for optimal adhesive bonding process