Seals and gaskets are meticulously manufactured to be able to withstand the exacting conditions under which they function. Not only does a gasket seal two distinct parts and allow the containment of extreme temperature fluids, steams and gases, but it must meld the sealed surfaces and not extrude.
Its requirements extend to remaining stable and whole as this lends to the durability of the application in which it is used. Taking these demanding necessities into consideration means a gasket manufacturer must use the latest technology and the best materials to produce an acceptable product.
Common Materials used in Gaskets
Gasket materials can be divided into four basic categories.
Standard gasket production involves fabricating from sheets of materials. The most common form of sheet material used is an elastomer mixed with anonymous filler/fibre.
- Butyl rubber: Resistant against ozone, gas, mild acids and alkalis; weakens on exposure to oil or fuel.
- Chlorosulphanated polyethene: Resistant against acids, alkalis, oil and fire.
- Ethylene propylene diene: Resistant against ozone, steam, acid, and alkaline liquids and vapours; unsuitable for proximity with solvents and aromatic hydrocarbons.
- Fluoroelastomer: Resistant to many corrosives, oils, aliphatic hydrocarbons and acid; unsuitable for proximity to esters, steams, vapours, amines and ketones.
- Rubber: Flexible with excellent resistance to acid/alkalis and salts; unsuitable for proximity to oil or solvents; weakens when exposed to long-term oxygen, ozone or UV/sunlight.
- Neoprene®: Withstands oils, ozone, sunlight/UV exposure, mild acids, alkalis, salts and solvents.
- Nitrile: Resistant to chemicals and temperatures, hydrocarbons and oils/fuels. Unsuitable foresters, ketones, strong oxidants and petroleum derivatives.
- Ask the experts at Specialist Sealing Products for more in-depth information about other elastomeric materials and their properties that are used in the manufacture of gaskets.
Fibrous materials are well suited to any application that requires constant fibrillation without extrusion or wear and tear.
- Aramid: Kevlar is the best-known use of aramid which is composed of polymer fibres linked in rings. This structure gives an aramid gasket strong stability when used within a medium temperature range.
- Asbestos: This material still has its uses in gasket manufacture because of its extreme resistance to heat as well as pliability and strength.
- Carbon fibre: A gasket made from carbon fibre does not retain or build up the heat; it disperses it, and this must be taken into consideration with the surrounding parts in the application. It is widely resistant to chemicals and acids/alkalis.
- Cellulose: The constituent that makes plant stalks; it is bendable yet strong. It imparts these properties to gaskets.
- Glass: Not brittle; strong and chemical resistant.
- Mineral wool: Gaskets made from this man-made fibre are best suited to medium temperatures.
Other Gasket Materials and Types
- Flexible graphite
- PTFE (Teflon™)
Gaskets types made from metallic materials are best suited to sealing higher temperatures and pressures. They are mostly used for applications such as compressors, pumps, valves and condensers. They are manufactured from carbon steel, titanium alloy, aluminium and copper.
When unsure whether an application should use a metallic, fibrous or elastomeric gasket, reach out to an expert at Specialist Sealing Products for advice on the best gasket type. Their extensive knowledge of seals and gaskets will set you up for success.