One of the most important properties in a gasket material is compressibility, and this leads many gasket buyers to think they need rubber. In many cases though there is an alternative: fiber gasket material. “Fiber gaskets” is a broad heading as there are many different types. Here we’ll explain what “fiber” means, how it differs from rubber and other rubber-like elastomeric materials, and when you might want to use it.
What is a Fiber Gasket?
Fiber gasket material is made through a process similar to papermaking. Strands of fiber are spread out and impregnated with a resin material. This dries to form sheets that are easily cut to shape.
Many different type fibers are used to produce gaskets with differing strength, compressibility and temperature ratings. These range from vegetable fiber and cellulose to more exotic materials like aramid, (a strong, heat resistant synthetic fiber.)
When additional compressibility is needed cork or a rubber binder (often NBR) is added. Alternatively, cellulose fiber material can be vulcanized to make a paper-like material that’s both hard and lightweight. When this has electrical insulating properties it’s known as “fish paper.”
Possibly the oldest type of gasket still in use is the vegetable fiber or “Detroiter” gasket. This is made from vegetable fibers impregnated with a glue-glycerine compound. It remains a popular choice in some applications.
Fiber Gasket Properties and Applications
Fiber material makes gaskets with high tensile strength, (so they’ll resist internal pressure,) and an upper temperature limit of 250 – 350°F. They have excellent resistance to chemicals, particularly oils, so are used in many industrial situations, especially chemical and petroleum product manufacturing.
The Contrast with Rubber
While true rubber is a natural product, the rubber used in gaskets is almost always a synthetic version. Synthetic rubbers function over a wider temperature range and are less vulnerable to damage by UV light. Commonly used materials are nitrile-butadiene rubber (NBR), styrene-butadiene rubber (SBR), neoprene and EPDM. Available in a range of thicknesses and grades of hardness, these have generally good compressibility but are vulnerable to the effects of petroleum oils.
Hennig Gasket & Seals manufactures custom gasket from a large variety of fiber gasket material. Contact us today for a fast quote.