Noise, vibration, and harshness, or NVH, is generated during the operation of an automobile and can travel through it by resonating through its structural components. When this happens, NVH will manifest itself in the vehicle cabin, becoming a nuisance to the operator. Noise in the operation of a vehicle is classified as any undesirable sound the driver may hear, and vibration is categorized as unintended shaking of the vehicle the driver may feel. Harshness can be described as the subjective experience of the operator towards the collective auditory and tactile sensations they receive from the vehicle while on the road.
How To Reduce NVH?
One of the main techniques used in automotive manufacturing to reduce sound and vibration is applying an adhesive layer of viscoelastic material to metal or composite components that are susceptible to vibration to damp noise and vibration. Momentive's SilGrip™ NVH adhesive is a viscoelastic material that provides absorption, isolation, and strong bonding capabilities.
Unlike SilGrip™ NVH, other materials used for damping may consist of acrylic- or rubber-based adhesives. While these types of adhesives provide sufficient damping at room temperature, the damping properties are significantly reduced when the temperature changes, to the extent that they are almost nonexistent outside 15°C–25°C.
Optimizing NVH with Momentive SilGrip™
Momentive SilGrip™ NVH is a fully customizable silicone pressure-sensitive adhesive system designed to provide optimum sound and vibration damping performance across a temperature range of −54°C to 380°C, which is much broader than that of traditional viscoelastic damping materials. Momentive SilGrip™ NVH also has wider peaks than other adhesive materials, as seen below. This enables better adhesive-part-number consolidation or a more versatile damping product near room temperature. Momentive SilGrip™ provides formulators with an easier-to-use, higher-performing, and more universal solution to NVH.
The SilGrip™ NVH system consists of a silicone pressure-sensitive adhesive (SilGrip™ NVH-PSA 1), a high-temperature modifier (SilGrip™ NVH-HT 1), and a low-temperature modifier (SilGrip™ NVH-LT 1). Mixing SilGrip™ NVH-PSA1 with either SilGrip™ NVH-HT 1 or SilGrip™ NVH-LT 1 can optimize damping properties for a specific temperature range. The mix ratios and chart below provide a starting point for maximizing performance damping properties at a specified temperature range with SilGrip™ NVH.
PSA1 Formulation Calculator
To calculate an exact mix ratio for SilGrip™ NVH-PSA1, enter the temperature at which you want damping properties to be maximized and your target solution mass into the calculator below.
The use of SilGrip™ SRC18 or BPO at 1%–3% is recommended as a catalyst for cross-linking and curing SilGrip™ NVH adhesives. It should be noted that peak damping is reduced by incorporating excessive catalyst. Therefore, the minimum amount of catalyst should be used to achieve good adhesion and optimize vibrational damping performance.
Preparation and Application of SilGrip™ NVH
The video below demonstrates the best practices for preparing and adhering Momentive SilGrip™ NVH to your surface component. It also provides an auditory example of the damping performance SilGrip™ NVH can provide.
Additional Benefits of SilGrip™ Pressure Sensitive Adhesives
SilGrip™ pressure-sensitive adhesives offer benefits beyond damping noise, vibration, and harshness properties within a vehicle. With their superior performance over acrylic- and rubber-based adhesives, SilGrip™ also provides several useful properties in automotive applications, as listed below.
UV Light Resistance
Resistance to solvents
Moisture and weathering resistance
Formulation latitude
Summary and Conclusion
With a rising demand for automobiles, especially those prone to NVH, such as electric vehicles, reducing NVH is critical to improving driver assessment of vehicle quality. This is especially true for luxury vehicles, which have the highest consumer expectations. SilGrip™ NVH pressure-sensitive adhesives not only reduce NVH over wider temperature ranges than other types of NVH adhesives but also provide outstanding performance in the most extreme climates and harsh environments. Click below to discuss your application with one of our experts and request a sample.
