Noise, vibration, and harshness (NVH) are the unwanted sounds and vibrations that are often generated by mechanical systems, engines, and other equipment. It’s a crucial factor in the design and performance of products, particularly in automotive, aerospace, and consumer electronics industries. Failure to control NVH results in poor quality products that are not comfortable to use, but there’s good news: foam materials are one of the best controllers of NVH.
What Causes NVH in Products?
There are many sources of NVH, including:
- Mechanical Forces: the movement of parts, such as engines, motors, and gear systems, generates vibrations and noise.
- Aerodynamic Forces: airflow around a product, such as a vehicle, can create noise and vibration.
- Structural Resonance: components vibrating at their natural frequencies can amplify noise and harshness.
- Material Properties: the inherent properties of materials used in construction can affect the transmission and damping of vibrations and noise.
What are the Dangers of NVH?
Failing to mitigate NVH can lead to some serious problems in products, including:
- Product Quality: excessive NVH can compromise the quality of a product by causing components to wear out faster, leading to malfunctions and breakdowns. It can also result in cosmetic damage, such as cracks and deformations.
- Durability: vibrations can cause fatigue in materials, leading to fractures and failures over time. Reducing NVH can enhance the durability of products by minimizing the stress on materials.
- Comfort: in products like vehicles and consumer electronics, high levels of NVH can significantly reduce user comfort. Noise and vibrations can cause discomfort, annoyance, and even health issues over prolonged exposure.
- Longevity: reducing NVH can extend the lifespan of a product by preventing premature wear and tear, thereby ensuring that components and systems operate smoothly and efficiently for longer periods.
How Foam Helps Prevent or Reduce NVH
Foam materials are excellent at damping vibrations due to their cellular structure, which absorbs and dissipates energy. When placed between vibrating components, foam reduces the amplitude of vibrations, thereby minimizing noise and harshness. The open or closed-cell structure of foam also aids in trapping sound waves, reducing the transmission of noise. This makes foam an effective material for soundproofing applications.
Since foam also provides cushioning that absorbs shocks and impacts, it helps further protect delicate components subject to NVH from becoming damaged. This is particularly important in packaging and transportation, where products are subjected to various forces.
The Best Types of Foam for Reducing Vibrations
- Polyurethane Foam: polyurethane foam is widely used for its excellent vibration damping and noise absorption properties. It is flexible, durable, and can be manufactured in various densities to suit different applications. It is commonly used in automotive interiors, machinery, and consumer electronics.
- Polyethylene Foam: polyethylene foam is known for its superior shock absorption and cushioning properties. It is also resistant to moisture and chemicals, making it ideal for industrial applications where durability is crucial. Polyethylene foam is often used in packaging, construction, and automotive industries.
- Neoprene Foam: neoprene foam is a versatile material with excellent resistance to temperature variations, making it suitable for both indoor and outdoor applications. Its ability to dampen vibrations and reduce noise makes it popular in automotive and marine industries.
- Zote foams: these specialized foam products are known for their high-performance characteristics in vibration damping and noise reduction. They are manufactured using a unique nitrogen expansion process that creates a highly uniform cell structure, enhancing their ability to absorb and dissipate vibrational energy effectively. This makes them ideal for applications in the automotive, aerospace, and industrial sectors where superior NVH control is required.
- EVA Foam: ethylene Vinyl Acetate (EVA) foam is highly effective at absorbing impacts and vibrations. It is lightweight, flexible, and offers good thermal insulation properties. EVA foam is commonly used in sports equipment, footwear, and industrial applications where vibration reduction is essential.
Manage NVH with Foam
Foam materials play a pivotal role in mitigating the issues of NVH by providing effective noise and shock absorption, and more. At Amcon, we can help you select a foam that mitigates NVH, and custom fabricate it to fit and properly protect your products. Need a foam sample? Have a question about NVH mitigation? Get in touch with our team today.