Fluorosilicone gaskets combine the high and low temperature resistance of silicones with the fuel and oil resistance of fluorocarbons. Some fluorosilicone gasket materials also resist abrasion and provide EMI shielding. Is fluorosilicone the right rubber for your gasketing application?
Fluorosilicones combine the temperature resistance of silicones with the fuel, oil, and solvent resistance of fluorocarbons. Applications for these extreme-environment elastomers include automotive, aerospace, defense, electronics, and semiconductor manufacturing.
For technical buyers and design engineers, however, choosing the right rubber can involve more than just specifying a temperature range, oil or fuel type, and industry. Is flurosilicone rubber right for your sealing and insulation application? If so, what type of fluorosilicone compound do you need? Some provide specialized properties that you might not expect.
Fluorosilicone Properties and Applications
Flurosilicone’s mechanical properties vary with service temperature, and some compounds provide resistance to abrasion and electromagnetic interference (EMI). In addition to fuel line seals, engine gaskets, and exhaust gas recirculating diaphragms, fluorosilicone rubber is used in O-rings, tank linings, protective boots for electrical equipment, and in plasma ashing equipment for the semiconductor industry. Metal-filled fluorosilicones provide electrical conductivity, too.
Fluorinated Silicone Rubber (FSR, FVMQ)
Like other silicone compounds, fluorosilicone rubber (FSR, FVMQ) resists high temperatures, low temperatures, ozone, aging, ultraviolet light, and weathering. Typically, FSR or FVMQ rubbers are blended with dimethyl silicones, elastomers that provide good temperature stability. Silicones, a large family of synthetic rubbers, are used in environmental sealing and are chemically inert. These elastomers also have good dielectric properties and are available as molded rubber products and extrusions.
FSR Rubber for Fluid Resistance and Abrasion Resistance
Fluorinated silicone rubber contains fluorine additions that impart resistance to hydrocarbon fluids such as jet fuels. These synthetic elastomers also resist oxidizing chemicals, chlorinated solvents, aliphatic and aromatic fluorocarbons, silicone oil, and animal and vegetable oils. Although some FSR rubbers have poor abrasion resistance, others have benefited from advancements in fluorosilicone chemistry. For example, some FSR elastomers have an abrasion resistance that’s superior to FKM or Viton.
Fluorosilicone Gaskets for Static and Dynamic Sealing
Traditionally, fluorosilicones were used only in static sealing applications. Thanks to their improved abrasion resistance, however, some FSR materials are now used in dynamic applications such as sliding shaft seals and rotating seals. Other types of oil-resistant rubbers are available, but FVMQ may be the right choice for your sealing application because of its fuel resistance, outstanding low-temperature flexibility, and low compression set.
Electrically-Conductive Fluorosilicone Gaskets for EMI Shielding
Fluorosilicone compounds that are filled with metal particles or thin strands of metal wire combine environmental sealing with EMI shielding. The insulation that these conductive shielding elastomers provide makes them a good choice for industrial, commercial, and military applications. Examples include fluorosilicones that are filled with silver-nickel or silver-aluminum particles, or that contain Monel or aluminum wires. Shielding silicones that that meet MIL-DTL-83528C requirements are available.
Custom Fluorosilicone Seals, Gaskets, O-Rings and More
Do you need help determining if fluorosilicone is right rubber for your application? If FSR or FVMQ rubbers meet your requirements, do you know which kind of compound you need? Elasto Proxy keeps hundreds of rubber profiles in stock, and can source fluorosilicone compounds that meet your application requirements. With our custom fabrication expertise, we can also create specialty flurosilicone seals, gaskets, O-rings, and other industrial rubber products.
How can we help you? Download this document to learn more about our technical design and custom fabrication capabilities.
I hope you’ve enjoyed this article. Please contact me if you have any questions.
Clyde Sharpe
General Manager at Elasto Proxy
