How Henkel’s high damping structural adhesive combines strength and vibration control in EVs

With the shift to electric mobility, not only is the powertrain changing, but also the way vehicles are perceived. What was once masked by engine noise, rolling sound and mechanical activity is now moving to the forefront of attention. For manufacturers, this is no longer just a comfort issue, but a development field that reaches deep into body structure, material selection, and production processes. Requirements for Noise, Vibration, and Harshness (NVH) are shifting noticeably. And with them, the pressure is increasing to find novel solutions that integrate seamlessly into modern vehicle architectures from both a structural and process perspective.

“With electric vehicles, the car as a whole becomes quieter, and that’s exactly what makes other noises suddenly noticeable,” says Jason Pfeifle, key account manager at Henkel. Creaking, rattling, or buzzing noises become far more apparent than in vehicles with internal combustion engines. At the same time, expectations for a quiet, high-quality cabin, especially in higher-end vehicle segments, have risen further.

Integrating strength and damping in one material system 

Henkel is addressing this development with a new high damping structural adhesive, Teroson EP 52 series, designed to combine two functions that have traditionally been treated separately in vehicle development: structural strength and vibration damping. The ambition behind this approach is significant. Until now, NVH optimisation has often followed an additive principle. Structural adhesives, weld points, or other joining technologies provide mechanical bonding and stiffness, while additional damping materials such as bitumen solutions, acoustic baffles or tapes are used to reduce noise and vibration. 

This approach works, but it increases material usage, weight, and system complexity. This is precisely where the new development comes in: it aims to treat damping not as a downstream measure, but as an inherent property of the joining material itself. 

The relevance of this approach is growing, particularly in electric vehicles. Sainath Jadhav, the chemist at Henkel responsible for developing the product, describes the shift in NVH dynamics. In conventional vehicle architectures with combustion engines, the powertrain was the dominant NVH source. With battery-electric vehicles, this picture changes fundamentally. The battery, as a large and heavy component located in the vehicle floor, introduces new load paths and different stress distributions into the structure. At the same time, noise sources such as road excitation and aerodynamic noise become more prominent, as they are no longer masked by the engine. As a result, the focus in body engineering is shifting: it is no longer just about stiffness, but also about how vibrations are generated, transmitted, and ideally reduced within the structure. 

Breaking NVH trade-offs in structural bonding 

This is exactly where traditional structural adhesives reach their limits. They perform well in terms of strength, stiffness, energy absorption, and structural integrity. However, they were not designed to actively damp vibrations. Jadhav describes the underlying conflict as almost fundamental from a materials science perspective: a very stiff material can efficiently transfer loads and reliably bond components, but lacks the elasticity required to dissipate vibrations. A softer material, on the other hand, can absorb vibrations but does not provide sufficient structural strength. “These two properties lie at opposite ends of the material spectrum,” he explains.

The solution Henkel now offers is an epoxy-based high damping structural adhesive. It is designed to combine medium structural strength with significantly enhanced damping performance compared to conventional structural adhesives. The adhesive can be processed in the body-in-white, fulfil structural functions and at the same time reduce vibrations exactly where sheets and structures are joined. From Henkel’s perspective, this represents not just a new material, but a step toward multifunctional materials. Nick Chudalla, strategy manager at Henkel, states that “in the past, you needed two materials for two functions. Today, we aim to combine those functionalities.” Such dual-function materials are part of a broader trend toward fewer parts, reduced complexity, and more efficient production.

The product did not originate from a purely theoretical research initiative, but from a concrete OEM requirement. According to Pfeifle, a leading automotive manufacturer approached Henkel with a clearly defined NVH challenge. The task was to develop a material that meets specific structural requirements while simultaneously addressing unwanted noise and vibration. Over several years, the formulation was gradually developed, tested, and refined. This alone illustrates that the result is not an off-the-shelf product, but a solution closely tied to a real vehicle application and specific production conditions. 

Designed for real-world production constraints 

What stands out about this development process is how strongly it was driven by production requirements. Initially, the focus was on damping, strength, and material properties. However, it quickly became clear that a chemically sound solution alone would not be sufficient. It had to fit into the existing manufacturing environment of OEMs. A material that only performs under ideal laboratory conditions has little value in body shop production. 

As a result, additional requirements became critical: pumpability at room temperature, robust behaviour during pretreatment, sufficient wash-off resistance, stable application via standard equipment, compatibility with welding processes and no need for additional investment on the customer side. Particularly in North America, Jadhav explains that many OEMs prefer materials that can be processed without heated pumping systems. The formulation therefore had to deliver not only the desired damping and strength characteristics, but also the right viscosity, flow behaviour and compatibility with existing dispensing systems.

Pfeifle emphasises how crucial this aspect is from a customer perspective. Any new material solution must integrate into existing body shop processes without requiring fundamental changes to production lines or additional capital expenditure. This is why compatibility with existing pumps, robotic systems, and application equipment was a key requirement from the outset. 

The adhesive needed to run on existing infrastructure, use established production cells, and be implemented without additional investment. For vehicle manufacturers, this is often a decisive factor: even the most promising innovation loses attractiveness if it requires new infrastructure or disrupts production. 

Targeting NVH-critical vehicle floor structures 

The first application focuses on an area of the vehicle that is particularly relevant for both structural and acoustic performance: the floor. This is where multiple sheet metal components are joined, welded, and processed further. These zones are especially critical for vibration transmission and therefore for the overall acoustic perception of the vehicle. Henkel sees the greatest potential for the new adhesive in these large metal-to-metal joining areas, where multiple structural layers come together.

Interestingly, weight reduction was not the primary driver in this specific development project. While lightweight design remains a key topic in automotive engineering—especially in the context of range, efficiency, and material substitution—the customer’s primary objective in this case was to solve an NVH-related issue. 

Nevertheless, the concept offers medium- to long-term potential for reducing both weight and complexity. If a single material can provide both structural and damping functions, additional damping materials or acoustic solutions can be reduced or partially eliminated. From Henkel’s perspective, this represents a clear strategic advantage: fewer materials, fewer interfaces, and reduced system complexity.

The new solution does not replace all existing acoustic measures, but it bridges the gap between structural bonding and damping. Henkel has conducted internal studies showing that damping adhesives can reduce vibration peaks in relevant frequency ranges, for example in BSR-related phenomena or in frequencies excited by road and tire interaction. The material is therefore intended to make a measurable contribution to structural NVH optimisation. 

Building a scalable platform for OEM adoption 

For Henkel, the story does not end with a single project. The company sees significant scaling potential beyond the initial customer. According to Pfeifle, discussions with additional OEMs are already underway, and further tests and trials are planned. Chudalla emphasises that the technology was not developed exclusively for one manufacturer. The intellectual property remains with Henkel, and the solution can be adapted to different customer requirements and deployed globally.

There is also a second important effect: the initial development has created a technological foundation that can accelerate future projects. Jadhav refers to a “toolkit” that is now available. When new OEMs approach Henkel with similar challenges, development no longer needs to start from scratch. The fundamental balance between damping, strength, and process compatibility has already been established. 

Future adaptations can therefore be implemented more quickly, even though each manufacturer and production environment brings its own requirements. This shortening of the path from problem to solution is likely to be a key factor in broader market adoption.