What material is used in the Manufacturing of MLV?
The first thing I would like to address is the Mass Loaded Vinyl composition. When the product first hit the market decades ago, barium was one of the raw materials in the manufacturing process. Today, due to advances in science and production, MLV is now manufactured from calcium carbonate combined with other propriety materials based on the manufacturer. Any article that states that barium sulfate is used in the manufacturing process would be incorrect.
Does MLV block or absorb sound?
Again, I have seen articles and blog posts saying that it does both, but that is not factual. Plain MLV as manufactured is a sound blocker. Imagine wrapping a room in Plain MLV; the MLV will block any sound from escaping the room.
Plain MLV, when combined with other raw materials, however, can become an absorber. The most common material used as the absorber is quilted fiberglass. The fiberglass is laminated to the MLV to create an absorber/decoupler product. Fiberglass is not the only absorber available. There are other materials that can be used as an absorber. However, fiberglass is often the most common material of choice.
How does MLV act as both an Absorber and Blocker?
When combined with other materials it can do both. It works on the principle that sound waves originating from a source will be initially absorbed by the fiberglass and then blocked by the mass loaded vinyl. Any reflected sound waves will further dissipate into the fiberglass absorber, and this is the only way MLV acts as an absorber. The material as manufactured (plain MLV) does not absorb sound waves; it only blocks them.
Is MLV fire-proof?
No, MLV is not fire-proof and will burn. Mass loaded vinyl that has a foil facing laminated to one side does receive an ASTM E-84 Class “A” rating. That’s the only way that the material can meet this rating. An interesting fact about MLV is that when lit it will ignite, but once the flame is removed, the material extinguishes itself often referred to as self-extinguishing.
Can I use MLV to soundproof my vehicle?
Yes, you can, but you should be aware that you will be adding significant weight to your vehicle, as higher densities of MLV weigh more. The other issue is that higher density MLV would not be as flexible. We would advise you to use a sound deadening product (such as dynamat) to soundproof your vehicle. Those products are more flexible and easier to install. You can find these on Amazon.