The following is a brief description of the basic elastomer families.

Fluorocarbon (FKM, Viton®)

Fluorocarbon, typically referred to as Viton® (Dupont Dow Elastomer), is renown for its high resistance to heat, and superior swell resistance in a wide variety of elements such as chemicals, ozone, hydrocarbon solvents, mineral oils, gasoline, and extended fuels. These highly fluorinated, carbon back boned polymers, exhibit very low gas permeability, as well as low compression set values and excellent aging characteristics. While the typical low temperature flexibility of FKM compounds is -15°F, specialty formulations are available for applications requiring cold flexibility down to -40°F. Standard FKM compounds provide for continuous service temperatures as high as 437°F.

FKM compounds are generally not resistant to polar solvents such as acetone, hot water, steam, glycol-based brake fluids, and low molecular weight organic acids.

Advantages:

• Excellent heat resistance
• Excellent chemical resistance
• Good mechanical properties
• Good compression set resistance

Disadvantage:

• Fair temperature resistance
• Not compatible with with glycol based brake fluids, amines, and superheated steam.

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Fluorosilicone (FVMQ)

Fluorinated Silicone takes the strong properties of silicone rubber and adds fuel resistance to the mix. This property provides excellent resistance to hydrocarbon fuels and mineral oils. It also has excellent low temperature flexibility down to -57°C (-70°F), and a high temperature limit of 177°C (350°F). Fluorosilicone's higher performance also comes at a higher cost.

Advantages:

• Excellent at temperature extremes
• Good resistance to petroleum oils and fuels
• Good compression set resistance

Disadvantages:

• Poor physical strength

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Kalrez© (FFKM)

Kalrez Perfluoroelastomer parts are the result of research which combines the rubbery properties of a fluoroelastomer (FKM) with the chemical stability of the fully fluorinated fluorocarbon resin. The product is a copolymer of the tetrafluoroethylene and perfluoromethyl vinyl ether with small amounts of a perfluorinated comonomer. The resultant polymer is essentially a rubbery analog of Teflon© fluorocarbon resin

The first commercial applications for Dupont's high performance elastomer were in 1971, and in 1975 the Kalrez trademark was adopted. By the late 1970's, 80% of Kalrez perfluoroelastomer business was in the oil patch. Today the predominant market applications for these compounds are CPI and semiconductor, but it also services critical applications in the aerospace, oil and gas, paint spray and pharmaceutical
industries (Kalrez 6230) as well. There are currently more than 25 different Kalrez compounds available to serve the marketplace. The three most widely used are:
Kalrez 7075, Kalrez 6375 and Kalrez 4079.

Please contact us at sales@buckeyrubber.com if additional information is required.

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