The following materials are used for Rubber Extrusions:
EPDM - Ethyylene Diene Monomer
(-50°C to +130°C)
EPDM has good abrasion and weathering properties with excellent water resistance, hence its use in WRAS approved applications.
EPDM is not resistant to mineral oils or hydrocarbon fuels, but is widely used in general engineering applications due to cost and performance qualities.
(-60°C to +170°C)
Fluorosilicone is generally similar to Silicone with a greater oil resistance but a reduced temperature range. It has poor tensile strength and poor resistance to abrasion. It is suitable for outdoor applications, having excellent weathering and ageing properties.
Hydrogenated Nitrile (-30°C to +125°C)
Designed to provide good performance and competitive cost in the range between Nitrile and Viton®.
It has good chemical resistance and will withstand thermal oxidation well. Particularly good in hot water and steam applications, but is not designed for use in applications requiring flame-retardant properties.
Natural Rubber (-30°C to +90°C)
Natural rubber has very good strength and resilience, and is commonly used for low temperature sealing applications and for its abrasion resistance.
Natural Rubber has poor resistance to mineral oils and has a limited temperature range.
Available in gasket, moulding and extrusion form.
Neoprene (-30°C to +95°C)
Neoprene is resistant to a wide variety of hostile conditions, such as chemicals, oil, water and weathering, and has the advantage of being flame-retardant.
Neoprene has only medium resistance to tearing, and will not withstand continuous use with fuels. Very good ozone resistance, making it suitable for outdoor applications.
Nitrile (-30°C to +120°C)
Nitrile is the most commonly used elastomer for general sealing applications as it is resistant to most mineral oils, hydrocarbon fuels, water and a wide range of chemicals.
It has poor ozone resistance either from sunlight or other external sources such as electric motors.
Available in all forms including 'O' Rings and sealing cord.
Silicone (-60°C to +200°C)
Silicone has a wide temperature range, good electrical insulation properties and has excellent resistance to animal and vegetable oils, water absorption, ozone and dilute acids.
It is not suitable for applications which require resistance to fuels, high tensile strength, abrasion resistance and tear strength.
Widely used in domestic appliances and medical applications.
Viton® (-20°C to +210°C)
Excellent resistance to mineral oils, fuels, water and most chemicals except Ketone solvents. Now widely used as the top sealing material in these environments at high temperatures, it has good flame resistance and very low gas permeability.
* Dupont Dow Elastomers Trademark
Gaskets, Seals and Rubber Mouldings