Common Elastomers & Their Characteristics
AFLAS* (TFE Propylene)Trade Name:
*Above...............................................................................3M This recently introduced material is unique due to its resistance to petroleum products, steam, phosphate esters and brake fluids. In some respects, it exhibits media compatibility properties similar to ethylene propylene and fluorocarbon. It has fair resistance to brake fluids and phosphate esters while exhibiting good resistance to petroleum oils. This material is finding interest for seal applications requiring petroleum resistance, steam and ammine resistance such as those applications encountered in the petroleum industry. Additional interest is being generated in applications requiring petroleum and brake fluid resistance or petroleum and phosphate ester resistance. The temperature service range for this material is -20°F to +400°F. Applications: Petroleum fluids & steam Petroleum fluids & ammines Petroleum fluids & brake fluids Petroleum fluids & phosphate ester ETHYLENE PROPYLENE (EPM, EPDM)(Ethylene Propylene Copolymer)
Trade Names: Nordel . . . . . . . . . . . . . DuPont Dow Vistalon . . . . . . . . . . . . Exxon Chemical Epsyn . . . . . . . . . . . . . .Copolymer Rubber Royalene . . . . . . . . . . . Uniroyal This material was introduced in 1961 and found broad acceptance in application requiring excellent resistance to Skydrol and other phosphate ester fluids at higher temperatures. In addition, compounds of this material exhibit excellent resistance to automotive brake fluids and steam. The temperature service range for these compounds is -65°F to +300°F.
FLUOROCARBON (FKM)(Vinylidene fluoride-hexafluoropropylene)
Trade Names: Fluorel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3M Viton . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DuPont-Dow Compounds of these polymers exhibit excellent resistance to petroleum products, low compression set and high temperature resistance. The low temperature capability is somewhat restricted, however, in some case the flow temperature sealing capability may be increased by specific design parameters. These materials meet the stringent requirements of Military Specifications Mil-R83248 and Aerospace Specifications AMS 7278, AMS 7279, and AMS 7280. They are especially good for hard vacuum service and low gas permeability. The normal temperature service range in fluorocarbon is -20°F to +400°F / + 450°F.
FLUOROSILICONE (FVMQ)Trade Names:
LS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Dow FSE . . . . . . . . . . . . . . . . . . . . . . . . . . . .GE These polymers exhibit good low/high temperature resistance with excellent resistance to petroleum oils and fuels. They are used in aerospace applications for fuel systems and systems requiring resistance to diester base lubricants to 350°F. Due to the limited strength and abrasion resistance of these materials, they are generally recommended for static applications only. The sealing temperature service range is -80°F to +350/400°F.
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NEOPRENE (CR) CHLOROPRENETrade Names:
Bayprene . . . . . . . . . . . . . Mobay Butchlor . . . . . . . . . . . . . . . Ditsugil This was the earliest of the volume American synthetic rubbers. Compounds from neoprene exhibit fair oil resistance, good ozone and weather resistance. Due to the excellent resistance to refrigerants such as Freon, neoprene compounds are used in refrigeration systems. The sealing temperature service range for these compounds is -65°F to +250/300°F.
NITRILE (NBR or Buna N)(Acrylonitrile-Butadiene Copolymers)
Trade Names: Chemigum . . . . . . . . . . . . . . Goodyear Hycar . . . . . . . . . . . . . . . . . .Zeon Chemical Krynac . . . . . . . . . . . . . . . . .Polysar Ny Syn . . . . . . . . . . . . . . . . .Copolymer Paracril . . . . . . . . . . . . . . . . .Uniroyal Perbunan . . . . . . . . . . . . . . . Mobay Compounds of these polymers are the backbone of the O-Ring line. Polymers vary from 18 percent to 50 percent acrylonitrile content. Resistance to petroleum products increases as acrylonitrile increases; conversely, low temperature flexibility decreases. Government specifications require low acrylonitrile. Nitrile Compounds can exhibit excellent compression set, tear and abrasion resistance. Unless especially compounded, they do not have good resistance to ozone, sunlight, or weather. They should not be stored near motors or other ozone generating electrical equipment. They should be kept from direct sunlight. Compounds from nitrile rubber can exhibit a temperature range of -65°F to +300°F, although no one formulation may exhibit the total range.
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Applications
Petroleum Fluids Water Silicone Fluids Ethylene Glycol Ozone & Weathering Amines Automotive Freon "R134A" |
Non-Compatible
Phosphate Esters Ketones Brake Fluids Strong Acids Keronsene Methanol/Ethanol Blends |
SILICONE (VMQ)
Trade Names:
Silastic . . . . . . . . . . . . . . .Dow
None . . . . . . . . . . . . . . . .General Electric
None . . . . . . . . . . . . . . . .Stauffer-Wacker
None . . . . . . . . . . . . . . . . Union Carbide
Silicones are noted for their excellent heat resistance, and are utilized in applications which expose seals to high temperature dry heat. They are not recommended for dynamic applications due to their relatively poor tensile and tear strength. They exhibit the best low temperature flexibility of all elastomers and can be used in static applications to -150°F. Silicones should be considered to be non-petroleum resistant, but can be used in specific high aniline point petroleum oils. The temperature service range for silicone compounds is -80°F to 450°F (All silicone formulations do not exhibit the capability of this entire range).
Silastic . . . . . . . . . . . . . . .Dow
None . . . . . . . . . . . . . . . .General Electric
None . . . . . . . . . . . . . . . .Stauffer-Wacker
None . . . . . . . . . . . . . . . . Union Carbide
Silicones are noted for their excellent heat resistance, and are utilized in applications which expose seals to high temperature dry heat. They are not recommended for dynamic applications due to their relatively poor tensile and tear strength. They exhibit the best low temperature flexibility of all elastomers and can be used in static applications to -150°F. Silicones should be considered to be non-petroleum resistant, but can be used in specific high aniline point petroleum oils. The temperature service range for silicone compounds is -80°F to 450°F (All silicone formulations do not exhibit the capability of this entire range).
Applications
High temperature (Dry heat) Low Temperature High Analine point oil |
Non-Compatible
Most petroleum oils Ketones Dynamic applications |
Assembly Solutions, Inc. has hundreds of different compounds used for our customers' custom molded parts. Below is a list of some of the other compounds. If you would like to request a quote, email [email protected]
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