Vibration damping is one of the most cost effective ways to reduce low frequency structure-borne noise. Free-layer and constrained-layer are the two most frequently used damping treatments.
In simple terms, vibration damping is similar to a suspension system in a car. It consists of a spring and a shock absorber.
Conventional damping materials are usually very heavy and are applied to the substrate as a free-layer. These materials are frequently referred to as 'mass-dampers'.
These mass-dampers are like the suspension system without the shock absorber. By adding weight to the system, it makes it harder to initiate the vibration. However, vibration energy remains in the system
Megasorber damping materials are engineered to be the "shock absorber" of the suspension system and remove the vibration energy from the system effectively.
The damping material must have high internal loss factor, and it can not be too soft nor too rigid. It is a challenge to balance the requirements of high loss factor and the modulus of the material. The following materials have been designed to have both optimized modulus and a high loss factor:
The damping material must be extremely viscous and soft. The loss factor of the material could be as high as 1.0. The following products all have a unique damping layer which is self-adhesive with high loss factor up to 1.0 :
Megasorber DT2S on 5mm Steel Plate
(Impact Noise Reduction)
Megasorber DT2A on 12mm Aluminum plate
(Impact Noise Reduction)
(1) System loss factor: is the total loss factor of a substrate after the damping treatment. It is measured as per ASTM E756-98: Standard Test Method for Measuring Vibration-Damping Properties of Materials.
(2) Decay rate (dB per second): is how fast the vibration decays. It is measured as per AS1937.10-1977: Determination of Damping Coefficient by The Thick Plate Method.
A system loss factor of 0.1 is equivalent to a noise reduction of 20 dB(A) for a large and freely suspended panel.
With Megasorber system loss factor calculation program, we ensure that the system loss factor is 0.10 as a minimum for a damping treatment on various substrates such as steel, aluminium, plastic and so on.
Typical noise reduction is between 8dB(A) to 15 dB(A) depending on the applications.
(1) Rain drop impact noise reduction of metal roofing: the typical noise reduction is 8 to 12 dB(A). Read more about "Rain Drop Impact Noise Reduction for Deaken University Performance Centre".
(2) Impact noise reduction for thick metal plate (12mm thick): a typical noise reduction of 15 dB(A) was achieved. Read more about "Impact Noise Reduction for Steel Wheel".
This can be achieved with (1) specially formulated damping material with high loss factor and mass and (2) 100% coverage of the substrate. Megasorber D10 and D20 products are specifically formulated to provide high vibration damping as well as high sound transmission loss.