When it comes to making a gasket, choosing the right material is critical. Every material gives as much as it takes away: can a durable part also be flexible? Can a thin piece withstand the heat? These are questions we must ask and answer before we even lay down the sheet to be cut. Now, imagine you need a resilient gasket that can be compressed without deforming, that can dampen vibrations, and maybe the ability to repel water would be useful. The material you’re looking for is felt! Let’s take a look at some of the key properties of felt gaskets to show just how useful this humble material really is.
What is Felt?
Felt is a textile material that can be made from natural fibers like wool, synthetic fibers like acrylic or rayon, or a mix of both. These fibers are condensed and pressed together; when it’s cut, felt leaves behind a clean edge which doesn’t ravel or fray, so regardless of the size, shape, or thickness of the sheet, there’s no need to refinish the edges. Similar to other materials used to make custom-cut gaskets, the varieties bring differing qualities.
3 Key Properties of Felt Gaskets
1. High Moisture-Wiking Ability
Natural felt’s key properties come from the fact that it’s made of wool and the natural qualities that material has. If you were to exercise on a cold day, you’d want to be insulated from the cold weather, but you wouldn’t want your sweat to stay on your body since this can cause frostbite. Not only does wool insulate, but it also absorbs moisture. In fact, wool can absorb up to a third of its own weight in water. When we’re talking about a felt gasket, the gasket can be exposed to damp conditions without sacrificing performance.
2. Flame Retardant
Despite being made from a natural fiber, wool ignites at a much higher temperature than a material like cotton and even some synthetic fibers. If it were to catch fire, though, wool burns much less quickly than other fibers. Interestingly, if a piece of wool were to be set on fire, the char it forms acts as an insulator and is self-extinguishing, so the wool can keep itself from burning up. Because of this, it’s common to find felt parts in places with a heightened probability of fire—you may not expect to find something made of felt in a complex piece of precision machinery like an airplane, but it is, in fact, highly likely to be found there!
One more reason felt is so useful is its high adaptability. A piece of felt can be less than 1/5 an inch thick upwards to 4 inches thick, which means it can be adapted to fit very tight tolerances. Adhesives can be applied to the felt so it can stick to other pieces or a permanent seal to other pieces of felt. Felt can also be treated with other coatings and impregnations such as nitrile to increase performance and efficiency. This adaptability allows felt to have a wide range of thickness, hardness, durometer, density, and even color.
While felt is commonly associated with clothing items like hats or boot liners or for making artistic projects like framing paintings or puppets (fun fact: Jim Henson’s Muppet characters are made of felt) felt’s other properties to make gaskets and seals to cushion and pad moving parts in the context of machinery. In the music world, felt’s natural noise dampening qualities make it great for instrument components like pads. Felt is a truly surprising material that can achieve a high level of performance if used correctly. Is felt the material you need to get the most out of your gaskets and seals? Breiner will help you find the innovative solutions you need when you need them!