How do die-cut components dampen noise and vibration?October 18 '21
BSR (buzz, squeak, and rattle) is a term used across industries such as automotive, aerospace, and electronics to describe the continuous noise or unpleasant squeaky sound that users may hear while operating a device. BSR remains one of the most prevalent and difficult challenges for engineers.
The effect may be caused by any moving components, poor bonding, or connection of two pieces. Whether it’s a cooling fan, a medical pump, or a washing machine, these moving components often generate friction that leads to damaging the parts over time. Moreover, hand-held or portable devices may be vulnerable to severe impact when dropped to the floor.
How can engineers minimize noise, vibration, and harshness?
That’s why minimizing noise, vibration, and harshness (NVH) is so important for manufacturers – it helps to ensure optimal performance and longevity of devices. In the past, engineers addressed the issue of NVH by inserting a piece of neoprene or rubber between two components. These components were held together by a screw, nut, or bolt.
The solution helped to reduce vibration, but the mechanical fasteners created a rigid bond that was susceptible to cracking or breaking.
Recently, engineers turned to a different method in the effort to address the problem of vibration at the source: vibration isolation. Where isolation isn’t an option, manufacturers can use noise and vibration dampeners. These dampeners absorb the noise and disperse it throughout the surface – reducing strain, tension, and vibration.
By using the right noise-canceling solutions, engineers can improve the device’s quality and the user experience. Replacing mechanical fasteners, solutions like acoustic foams, tapes, and adhesives give us a wide range of acoustic control options, combining high resiliency and shock absorption.
Examples of die-cut components for noise and vibration damping
Die-cut components help to address the noise and vibration design issues successfully. Melrose engineers are well-versed in using alternatives in these three product families to benefit from their unique characteristics and advantages.
1. Urethane foams
Urethane foams under the brand name of PORON® are open-celled materials characterized by high dimensional stability and excellent viscoelasticity. What does this mean? That the foams work well under continued vibration.
Urethane foams don’t collapse under pressure and always recover to 99% of their original dimension, thanks to their remarkable resilience to stress, relaxation, and compression. They come in various structures, ranging from exceptionally soft, very soft, to very firm. That way, engineers can provide consistency and reliability across applications.
The foams are flame retardant, chemically resistant, and can withstand temperatures from -40°C to 90°C. They also offer strong absorption for medium to high impact and have excellent gap filling, sealing, and gasketing characteristics.
PORON® urethane foams come in two variants: supported and unsupported. The supported foams include a thin layer of PET film backing on one side. Unsupported foams tend to be more common on the market today.
High-quality materials like BISCO® silicones are made of materials that are cellular, solid, or specialty silicone. They come with similar features and benefits to PORON® urethane foams.
However, silicones have something extra – an incredibly high flame resistance and the ability to withstand high temperatures. Cellular silicones can have various thicknesses and feature a strong compression resistance and tensile strength. Solid silicones are formed of a solid rubber-like substance and come in durometers ranging from 10 to 40 Shore A. Specialized silicones (that include both cellular and solid silicones) are available in durometers ranging from 40 to 70 Shore A.
3. Vibration damping tapes
The vibration dampening tapes from manufacturers like 3M include a soft aluminum backing that reduces resonance noise, vibration, and strain. The tapes can sustain up to 50 pounds per square inch of strength and are used to connect irregular and uneven surfaces.
These high-viscoelasticity pressure-sensitive tapes also decrease tension and disperse noise throughout the surface. Due to their high viscoelasticity, the very high bond (VHB) tapes come with dampening qualities similar to vibration damping tapes.
Reduce noise, vibration, and harshness with Melrose
Our engineers have years of experience in providing high-quality die-cut components that address the most important issues related to noise and vibration. By collaborating with Melrose, you gain access to decades of experience and top expertise in the field.
Get in touch with us and tell us more about your project’s requirements – our engineers will help you at every step of the way.