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Home , Embrittlement, Nitrile rubber, Silicone rubber

6 Material Selection Guide

Basic Concepts of Rubber What is ? The long, flexible polymeric chains of rubber, What is “Rubber”? when heated, react with vulcanizing agents to form “Rubber” refers to elastomeric compounds that three-dimensional structures. These vulcanizing agents consist of various monomer units forming (usually or peroxide) are necessary to facilitate that are heat cured (vulcanized). Polymers are long chemical crosslinking of polymeric chains. Once molecular chains and are derived from the Greek the rubber has been vulcanized or “cured”, physical “poly” (many) and “meros” (parts). The base monomer properties are enhanced and the compound is more or monomers is used to classify the type of rubber, for resistant to deterioration. example: , or . What is Compression Set? What is a Rubber Compound? Elastic recovery is a measure of the ’s Rubber is composed of many different ingredients ability to return to its original shape once a 6 that include the base elastomer, vulcanization agents, compressive force has been removed. Failure of the fillers and . For example, the addition of seal to return to its original shape after compression is fillers can reinforce or modify properties, or additional the condition termed “compression set” and all seals can increase elongation and lower durometer. exhibit some degree of compression set. Determination Why Does Rubber Act “Rubbery”? of the amount of compression set is governed by ASTM designation D395 test procedure. Rubber is considered highly viscous liquid or an elastic solid. The polymeric chains in rubber tend to What is the difference between a Thermoset be very long and flexible by nature and can rotate and Thermoplastic? about their axis, which results in an entangled mass of One classification method of polymeric materials contorted chains. is according to physical properties at elevated When a deformation of the rubber occurs, these temperatures. Thermoset polymers become tangled chains uncoil and recoil when the force permanently “set” in the presence of heat and do is released. Therefore, elastic rebound or rubbery not soften in the presence of subsequent heating. behavior is possible due to contortions of long, flexible Conversely, a thermoplastic material will soften when polymeric chains, which allow rubber to be so resilient. heated (and eventually liquefy) and harden when cooled. This process is reversible and repeatable, as How is Rubber Made? opposed to thermoset polymers where the process is The base is the primary component of irreversible. Also, thermoset polymers possess superior all rubber recipes and is selected in order to obtain mechanical, thermal, and chemical properties as well specific chemical and physical properties in the final as better dimensional stability than thermoplastic product. Processing aids and softeners, such as oils . This is why thermoset (rubber) parts are and plasticizers, modify rubber to aid in mixing or generally preferred for sealing applications. molding operations. Sulfur is one of the most widely This section contains descriptions of the elastomers used vulcanizing agents to promote crosslinking used in seal applications. These elastomers form the which is used in conjunction with accelerators and base of a wide variety of compounds, designated for accelerator activators to reduce cure times and specific applications. Every compound has specific enhance physical properties. black is one characteristics and many compounds have common of the most common fillers because it reinforces attributes. Therefore, it is important to consider the molecular structure. Antidegradants, such as all aspects of the compound prior to use. Also, as and antiozonants, retard the deterioration compound availability is customer driven, lead time of rubber products. Lubricants, colors or any other may vary. miscellaneous ingredients may also be added. www.applerubber.com 60 1.800.828.7745 (US & Canada Only) • +1.716.684.6560 (International) Material Selection Guide

Chemical Compatibility Table Chloroprene (Neoprene)  Please see the Seal Design Guide Online Trade Name(s): for the full “Chemical Compatibility” table. Neoprene ... DuPont Performance Elastomers www.applerubber.com/login/index.cfm Baypren ... ASTM D1418 Designation: CR Buna-N (See Nitrile) ASTM D2000/SAE J200 Type, Class: BC, BE Butyl Apple Compound Designation: CR Standard Color: Black Trade Name(s): Description: One of the earliest of the synthetic Exxon Butyl ... Exxon Chemical materials to be developed as an oil-resistant substitute Polysar Butyl ... Bayer Polymer for , Neoprene is a homopolymer of ASTM D1418 Designation: IIR chloroprene (chlorobutadiene). ASTM D2000/SAE J200 Type, Class: AA, BA Key Use(s): Numerous component uses in the transportation field. Recommended for exposure to Apple Compound Designation: BU weathering. Preferred sealing material for refrigeration Standard Color: Black industry. Description: An all-petroleum product, Butyl is Temperature Range: Standard Compound: a copolymer of isobutylene and isoprene and has -40°F to +250°F. Special Compounds: -67°F to +250°F. largely been replaced by Ethylene Propylene since (Dry Heat Only) its introduction. Hardness (Shore A): 40 to 90. Key Use(s): Highly effective in vacuum sealing Features: Neoprene can be used in innumerable applications. Good seal for hydraulic systems. sealing applications due to its broad base of such Temperature Range: Standard Compound: desirable working properties as: good resistance to -50°F to +250°F. petroleum oils; good resistance to , sunlight Hardness (Shore A): 30 to 90 and aging; relatively low compression set; good resilience; outstanding physical toughness; and Features: With outstanding low permeability to reasonable production cost. gases, Butyl is especially effective in vacuum sealing ® applications. It also features good to excellent Due to its excellent resistance to Freon and ammonia, resistance to ozone and sunlight aging. Neoprene is also widely accepted as a preferred material for refrigeration seals. Butyl further features excellent shock dampening capabilities. Only slightly affected by oxygenated Limitations: Neoprene is generally attacked by solvents and other polar liquids, Butyl is often utilized strong oxidizing acids, esters, ketones, chlorinated, in seals for hydraulic systems using synthetic fluids. It aromatic and nitro hydrocarbons. is good with MEK, and silicone fluids and greases. Because Nitrile is economically competitive with Limitations: Because it is a petroleum product, Butyl Neoprene, and generally has superior performance has poor resistance to hydrocarbon solvents and oils, characteristics in most situations, it has largely replaced ® and diester-based lubricants. Halogenated butyl has Neoprene in the O-rings of today. been introduced to expand oil and chemical resistance to this polymer. Chlorobutyl and Bromobutyl have better resistance. These polymers have been accepted by the medical industry for stoppers and septumns for pharmaceutical applications.

61 www.applerubber.com 1.800.828.7745 (US & Canada Only) • +1.716.684.6560 (International) Epichlorohydrin Ethylene/Acrylic (Vamac®) Trade Name(s): Trade Name(s): Hydrin ... Zeon Vamac® ... DuPont Dow Elastomers ASTM D1418 Designation: CO, ECO ASTM D1418 Designation: AEM ASTM D2000/SAE J2000 TYPE, CLASS: CH ASTM D2000/SAE J200 Type, Class: EE, EF, EG, Apple Compound Designation: EH EA Standard Color: Black Apple Compound Designation: VA Description: Available in homopolymer (CO), Standard Color: Black copolymer (ECO), and terpolymer (GECO) formats, Description: A copolymer of ethylene and methyl Epichlorohydrins are oil resistant compounds. acrylate, with a small amount of a third monomer Key Use(s): Ideal for fuel and air conditioning system added to provide a cure to active groups in the 6 components. Used in the petroleum industry where a polymer chain, Vamac® exhibits properties similar little higher temperature capability than NBR is required. to those of polyacrylate, but with an extended low Temperature Range: Standard Compound: temperature limit and better mechanicals. -40°F to 275°F. Key Use(s): Seals for automotive applications, Hardness (Shore A): 50 to 90 such as automatic transmissions and power steering systems. Features: Epichlorohydrin features excellent resistance to hydrocarbon oils and fuels; low solvent Temperature Range: Standard Compound: and gas permeability; excellent resistance to ozone -13°F to +338°F. (Dry Heat Only) and weathering; and stable cycling from low to high Hardness (Shore A): 50 to 90. temperature. Good replacement to butyl when gas Features: Ideal for automotive sealing uses, Vamac® permeability and oil resistance are needed. features excellent heat resistance, outstanding Limitations: Compression set is only “fair” resistance to ozone and sunlight aging, moderate at elevated temperatures (250°F to 275°F). resistance to swelling in oils, and very low permeability Epichlorohydrin is attacked by ketones; esters; to gases. aldehydes; chlorinated and nitro hydrocarbons; and With a maximum reinforced tensile strength of is not recommended for exposure to brake fluids. 2,500 psi, Vamac®’s mechanical properties of adhesion

to metals, tear resistance, flex life, abrasion resistance and compression set resistance are all rated as “good.” Resistance to water, engine coolant mixtures (glycols), dilute acids and alkalis is also good. Limitations: Vamac® is not recommended for exposure to concentrated acids, aromatic hydrocarbons, gasoline, ketones, brake fluids and phosphate esters.

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Ethylene-Propylene Fluorocarbon (Viton®) Trade Name(s): Trade Name(s): ® Nordel ... Dow Chemical Viton ... DuPont Performance Elastomers Kaltan ... DSM Elastomers Fluorel ... 3M Company Royalene ... Chemtura Corporation Technoflon ... Solvey Solexis, USA ASTM D1418 Designation: EPDM ASTM D1418 Designation: FKM ASTM D2000/SAE J200 Type, Class: ASTM D2000/SAE Type, Class: HK AA, BA, CA, DA Apple Compound Designation: VT Apple Compound Designation: EP Standard Color: Black Standard Color: Black Description: Combining high temperature resistance Description: A copolymer of ethylene and propylene with outstanding chemical resistance, Fluorocarbon- (EPR), combined with a third comonomer adiene based compounds approach the ideal for a universal (EPDM), Ethylene Propylene has gained wide seal O-ring material. industry acceptance for its excellent ozone and Key Use(s): Seals for aircraft engines. Seals for chemical resistance characteristics. automotive fuel handling systems. High temperature/ Key Use(s): Outdoor weather resistant uses. low compression set applications. Wide chemical Automotive brake systems. Automobile cooling exposure situations. Hard vacuum service. systems. Water applications. Low torque drive belts. Temperature Range: Standard Compound: Temperature Range: Standard Compound: -13°F to +446°F. Special Compounds: -40°F to +446°F. -40°F to +275°F. Special Compound: -76°F to 302°F. Hardness (Shore A): 45 to 90. Hardness (Shore A): 40 to 95. Features: High fluorine grades offer higher resistance Features: When compounded using peroxide to swell in high octane and oxygenated fuel blends. agents, high temperature service can reach This gives superior performance in Ethanol/Methanol +302°F. Good resistance to acids and solvents blended gasoline. Base resistant grades offer improved (i.e. MEK and Acetone). resistance to based oil protectants found in new transmission oils. Also, improved resistant to steam for Limitations: Have no resistance to hydrocarbon higher temperature services. Low temperature bases fluids. can improve performance to -40°F. New polymers being offered have improved chemical resistance and low temperature performance. Viton® Extreme™ ETP offers similar chemical compatibility as Kalrez™ with temperature resistance to +446°F. Special compounds, using new polymer technologies, provide improved low temperature performance with a TR(10) of -40°F and brittleness to -76°F. Limitations: Fluorocarbons are not recommended When it is said that an elastomer is good for an for exposure to ketones, , low molecular weight Rule application, it is meant that some compounds which of esters and ethers, nitro hydrocarbons, hot hydrofluoric Thumb include that elastomer are acceptable, not all. For instance, some compounds of EP are good for brake or chlorosulfonic acids, or Skydrol® fluids. They are also fluid applications, but most are not acceptable. not recommended for situations requiring good low temperature flexibility.

63 www.applerubber.com 1.800.828.7745 (US & Canada Only) • +1.716.684.6560 (International) Fluorosilicone Liquid (LSR) Trade Name(s): LSR is a low viscosity silicone elastomer intended Silastic LS ... Dow Corning Corporation for use in liquid injection molding (LIM) equipment. FSE ... Momentive Performance Materials It offers high thermal stability and flexibility at low temperatures, high transparency and is easily colored. ASTM D1418 Designation: FVMQ Also, self-lubricated and electrically conductive grades ASTM D2000/SAE J200 Type, Class: FK are available as well as FDA and medical compliant grades. Liquid silicone rubber is widely used to Apple Compound Designation: FS mold complex profiles because of its excellent flow Standard Color: Blue characteristics. Description: Fluorosilicone combines the good high and low temperature stability of with the fuel, Medical Grade Silicone oil, and solvent resistance of Fluorocarbons. When properly prepared, possible benefits 6 Key Use(s): Aerospace fuel systems. Auto fuel include fulfillment of USP Class VI and ISO 10993 emission control systems. Primarily for static requirements, embrittlement from gamma sterilization, sealing applications. sterilizable with EtO/steam. Also, this grade of silicone is generally transparent due to class requirements. Temperature Range: Standard Compound: Limited medical grade pigments are available. -75°F to +400°F. Limitations: Generally, low abrasion and tear Hardness (Shore A): 40 to 80. resistance, and high friction characteristics preclude Features: Fluorosilicone is most often used in silicones from effectively sealing some dynamic aerospace applications for systems requiring fuel and/ applications. Silicones are also highly permeable or diester-based lubricant resistance up to 400°F. to gases and are generally not recommended for Although generally specified for aerospace use, due exposure to ketones (MEK, acetone) or concentrated to its excellent fuel resistance and high temperature acids. stability, Fluorosilicone is becoming an increasingly popular material for a wider range of sealing applications. Featuring good compression set and resilience properties, fluorosilicone compounds are suitable for exposure to air, sunlight, ozone, chlorinated and aromatic hydrocarbons. Limitations: Due to limited physical strength, poor abrasion resistance, and high friction characteristics, Fluorosilicone elastomers are not generally recommended for dynamic sealing. They are predominately designed for static sealing use. They are also not recommended for exposure to brake fluids, hydrazine, or ketones.

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Natural Rubber Nitrile (Buna-N) ASTM D1418 Designation: NR Trade Name(s): Nipol ... Zeon Krynac ... Bayer Polymer ASTM D2000/SAE J200 Type, Class: AA Nysyn ... DSM Elastomers Chemigum ... Eliokem Apple Compound Designation: NA ASTM D1418 Designation: NBR Standard Color: Black ASTM D2000/SAE J200 Type, Class: BF, BG, BK, CH Description: Natural Rubber is the vulcanized product of the juice of the Hevea tree (latex). Apple Compound Designation: BN Key Use(s): Seals in food and beverage applications. Standard Color: Black Most popular material for non-hydraulic sealing Description: Presently, the seal industry’s most widely applications. Mainly used for dampeners due to its used and economical elastomer, Nitrile combines excellent ability to absorb vibration. resistance to petroleum-based oils and fuels, silicone greases, hydraulic fluids, water and alcohols, with a Temperature Range: Standard Compound: good balance of such desirable working properties as -58°F to +158°F. (Dry Heat Only) low compression set, high tensile strength, and high Hardness (Shore A): 40 to 90. abrasion resistance. Use of Carboxylated Nitrile can have Features: Natural Rubber features high tensile superior abrasion resistance, while still having improved oil strength, high resilience, high abrasion and high tear resistance. resistance properties, with a good friction surface and Key Use(s): Oil resistant applications of all types Low excellent adhesion to metals. Until the invention of temperature military uses. Off-road equipment. Automotive, synthetic elastomers in the 1930’s, Natural Rubber was marine, aircraft fuel systems. Can be compounded for FDA the only polymer available for O-ring manufacture. applications. Natural Rubber features good resistance to organic Temperature Range: Standard Compound: -40°F to acids and alcohols, with moderate resistance to +257°F. Special Compounds: -76°F to +275°F. (Dry Heat aldehydes. Only) Limitations: Not widely used in sealing industry Hardness: (Shore A): 40 to 90. due to poor compression set performance and lack of Features: Comprised of the copolymer and resistance to many fluids. , in varying proportions. Use of Carboxylated Nitrile can have superior abrasion resistance, while still having improved oil resistance. Limitations: Nitrile compounds are attacked by small amounts of Ozone. Phthalate type plasticizers are commonly used in compunding . These plasticizers can migrate out and cause problems with certain . Also, new regulation on certain phthalates have limited their use.

65 www.applerubber.com 1.800.828.7745 (US & Canada Only) • +1.716.684.6560 (International) Nitrile, Hydrogenated (HNBR) Perfluoroelastomer Trade Name(s): Trade Name(s): Zetpol ... Zeon Co., Ltd. Chemraz® ... Green, Tweed & Co. Therban ... Bayer Kalrez® ... DuPont Performance Elastomers ASTM D1418 Designation: HNBR Tecnoflon PFR ... Solvay Solexis ASTM D2000/SAE J200 Type, Class: DH ASTM D1418 Designation: FFKM Apple Compound Designation: NB ASTM D2000/SAE J200 Type, Class: Standard Color: Black No Designation at Time of Publication Description: HNBR is the product of the Apple Compound Designation: KA hydrogenation of Nitrile, resulting in varying degrees Standard Color: Black of saturation of the polymeric chain, along with a range Description: FFKM parts are made from a of enhanced physical strength and chemical resistance 6 perfluoroelastomer possessing exceptional resistance properties. to degradation by aggressive fluids and/or gases. Key Use(s): ALL oil resistant applications, Key Use(s): Seals for use in the chemical and including exposure to such oil additives as detergents, petroleum industries as well as for the manufacturing anti-oxidants and anti-wear agents. Exposure to of semiconductors and analytical and process oil soured with metal sludge. Seals for oil well instruments. It is also used for high temperature applications. Seals for automotive fuel handling applications and for paint and coating operations. systems. Seals for general industrial usage. Temperature Range: Temperature Range: Standard Compound: Standard Compound: -13°F to +600°F. -30°F to +300°F. (Dry Heat Only) Special Compounds: -76°F to +347°F. Hardness (Shore A): 65 to 90 Hardness (Shore A): 50 to 90 Features: FFKM combines the toughness of an elastomeric material with the chemical inertness of Features: Like Nitrile, increasing acrylonitrile content Teflon®. It resists attack by nearly all chemical reagents improves oil resistance at a cost of reduced low and provides long-term service where corrosive temperature performance. additives can cause other elastomers to swell or Limitations: Like Nitrile, HNBR is not recommended degrade. In addition, FFKM parts are less likely to for exposure to ethers, esters, ketones, or chlorinated cold flow than Teflon seals. hydrocarbons. Limitations: Withstanding degradation by virtually ALL chemicals, FFKM can swell significantly when exposed to some fluorinated solvents, fully halogenated freons and uranium hexafluoride. In addition, FFKM parts should not be exposed to molten or gaseous alkali metals. As the thermal coefficient of expansion for FFKM is stated by the manufacturer to be “about 50% greater than for fluoroelastomers,” gland volume may have to be increased to allow for this expansion in elevated temperature situations. Because of its high cost, FFKM is generally used when no other elastomer is appropriate.

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Polyacrylate Polysulfide Trade Name(s): Trade Name(s): HyTemp ACM ... Zeon Thiokol® (types A, B, FA, ST) ... Thiokol Corp. Acralen A ... Bayer Polymer ASTM D1418 Designation: T ASTM D1418 Designation: ACM ASTM D2000/SAE J200 Type, Class: AK, BK ASTM D2000/SAE J200 Type, Class: DH; DF Apple Compound Designation: TH Apple Compound Designation: PY Standard Color: Black Standard Color: Black Description: Another of the early developed Description: Polyacrylates are copolymers (ethyl synthetic elastomers, Polysulfide offers a remarkable acrylates) possessing outstanding resistance to combination of solvent resistance, low temperature petroleum fuels and oils. flexibility, flex crack resistance, oxygen and ozone Key Use(s): Sealing automatic transmissions & power resistance, and gas impermeability. steering systems. Sealing petroleum oils up to 300°F. Key Use(s): Seals for paint and coatings and Temperature Range: Standard Compound: insecticide industry use. -25°F to +300°F. Temperature Range: Standard Compound: Hardness (Shore A): 40 to 90. -50°F to +225°F. Features: With excellent resistance to hot oil, Hardness (Shore A): 50 to 80 automatic transmission and Type A power steering Features: Resistant to a wide range of solvents, fluids, the greatest use for Polyacrylate is found in including ketones, ethers, and aromatic hydrocarbons. automobile manufacture, where O-rings of this material Polysulfide has gained wide acceptance as a seal are employed to seal components of automatic material for paints and coatings, and insecticides. transmission and power steering systems. Limitations: With poor heat resistance, poor Highly resistant to sunlight and ozone degradation, mechanical strength and compression set properties, Polyacrylate also features an enhanced ability to resist Polysulfides are not as versatile as other elastomers flex cracking. from a performance standpoint. They are also not Limitations: While resistance to hot air aging is recommended for exposure to mercaptans, esters, superior to Nitrile, Polyacrylate strength, compression amines, chlorinated or nitro hydrocarbons. set, water resistance properties and low temperature capabilities are inferior to many other polymers. Polyacrylates are also not generally recommended for exposure to alcohol, glycols, alkalis, brake fluids, or to chlorinated or aromatic hydrocarbons.

67 www.applerubber.com 1.800.828.7745 (US & Canada Only) • +1.716.684.6560 (International) ® (Teflon®) Limitations: Teflon is hampered by very poor elastic Polytetrafluoroethyne memory at room, or low temperatures. This presents Trade Name(s): problems in O-ring installation, requiring extra care to Teflon® ... DuPont Dow Elastomers be taken in control over O-ring I.D. stretch. Heating TFM ... Dyneon Teflon® in boiling water, or in a controlled oven, to 200°F ASTM D1418 Designation: FEP is said to enable an O-ring stretch of 10 to 20% to be achieved, thereby assisting installation, and helping to ASTM D2000/SAE J200 Type, Class: assure a tight fit. No designation at time of publication. Because of its poor tear resistance, during O-ring Apple Compound Designation: TF installation particular care should be taken to avoid Standard Color: White nicking or scratching Teflon®, as imperfections will Description: Teflon® is a tough, chemically inert cause O-ring leakage. polymer possessing an incredible working temperature Finally, the tendency of virgin Teflon® to cold flow over range. time, when used in gasket type applications, may 6 Key Use(s): Seals for wide chemical exposure situ­ require special material compounding (with fillers) to ations, with special emphasis on temperature extremes. control such “creep” in critical sealing situations. For static and SLOW INTERMITTENT dynamic situations. Temperature Range: Standard Compound: -300°F to +450°F. Hardness (Shore A): 98. Features: Teflon® is inert to virtually all industrial chemicals, even at elevated temperatures. Seals fabricated from this material feature outstanding weather resistance, high resistance to ozone, and high resistance to the degrading effects of exposure to such solvents as acetone, MEK, and xylene. Possessing average elastomer characteristics of 2,500 to 3,500 psi tensile strength, and 300% elongation, they are tough, impact resistant, low friction, non-twisting performers over an extremely wide temperature range.

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Temperature Range: Standard Compound: , Cast -30°F to +175°F. Trade Name(s): Hardness (Shore A): 70 and 90. Vibrathane ... Uniroyal Cyanaprene ... American Cyanamid Features: With tensile strength of up to 6,000 psi, Polathane ... Polaroid elongation of 350 to 650%, compression sets of 10 to 25%, and exceedingly high abrasion resistance, the ASTM D1418 Designation: No designation at time physical properties of Cast Polyurethane are among the of publication. best of all O-ring elastomers. ASTM D2000/SAE J200 Type, Class: Although they swell slightly upon exposure, Cast No designation at time of publication. Polyurethane compounds feature excellent resistance Apple Compound Designation: CP to mineral-based oils and petroleum products, aliphatic Standard Color: Amber solvents, alcohols and ether. They are also compatible with hydraulic fluids, weak acids and bases, and mixtures Description: Cast Polyurethane is outstanding containing less than 80% aromatic constituents. over other O-ring elastomers in abrasion resistance and tensile strength. Additionally, Cast Polyurethane Limitations: Cast are not surpasses the performance of Millable Polyurethane in recommended for exposure to concentrated acids and its higher tensile strength, greater elongation, bases, ketones, esters, very strong oxidizing agents, wider temperature range, and lower compression pure aromatic compounds and brake fluids. With the set characteristics. exception of special compounds, they are also not recommended for exposure to hot water or steam. Key Use(s): Seals for high hydraulic pressures. Situations where highly stressed parts are subject to wear. Used for wheels, rolls, slurry parts, bumpers, couplers, and shock absorbers. Wiper seals for axially moving piston rods.

69 www.applerubber.com 1.800.828.7745 (US & Canada Only) • +1.716.684.6560 (International) Polyurethane, Millable Silicone Trade Name(s): Trade Name(s): Millathane® ... TSE Industries Inc. Elastosil ... Wacher ASTM D1418 Designation: AU, EU Silastic ... Dow Corning Silplus ... Momentive Performance Materials ASTM D2000/SAE J200 Type, Class: BG ASTM D1418 Designation: MQ, PMQ, VMQ, Apple Compound Designation: MP PVMQ Standard Color: Black ASTM D2000/SAE J200 Type, Class: Description: Millable Polyurethane is outstanding FC, FE, GE over most other O-ring elastomers in abrasion Apple Compound Designation: SL resistance and tensile strength. Standard Color: Red Key Use(s): Seals for high hydraulic pressures. Situations where highly stressed parts are subject Description: A group of elastomers, made from to wear. , oxygen, and carbon, Silicones are 6 renowned for their retention of flexibility and low Temperature Range: Standard Compound: compression set characteristics, within one of the -30°F to +175°F. widest working temperature ranges for elastomers. Hardness (Shore A): 40 to 90 Key Use(s): Static seals in extreme temperature Features: Millable Polyurethane offers superior situations. Seals for medical devices, compatible with seal performance in hydraulic situations, where high FDA regulations. pressures, shock loads, or abrasive contamination Temperature Range: Standard Compound: is anticipated. -85°F to +400°F. Special Compounds: -148°F to Millable Polyurethane possesses chemical compatibility +400°F. similar to that of Nitrile, offering good resistance to Hardness (Shore A): 5 to 80 petroleum-based oils, hydrocarbon fuels and hydraulic fluids, the oxidizing effects of ozone, and the aging Features: Phenyl (PVMQ) based silicones can effects of sunlight. It also has good tear resistance. perform to -148°F. New polymers can take short term to 600°F. Limitations: Unless specially compounded, at elevated temperatures Millable Polyurethane begins to soften, losing its physical strength and chemical Rule Material cost does not correlate with performance, resistance advantages over other polymers. of Thumb it depends on the application. Tending to rapidly deteriorate when exposed to concentrated acids, ketones, esters, chlorinated and nitro hydrocarbons, Millable Polyurethanes are also prone to hot water and steam degradation.

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Styrene Butadiene Tetrafluoroethylene/Propylene (Aflas®) Trade Name(s): Trade Name(s): ® Too numerous to list. Aflas ... Asahi Glass Co., Ltd. TBR ... Dupont Performance Elastomers ASTM D1418 Designation: SBR ASTM D1418 Designation: FKM ASTM D2000/SAE J200 Type, Class: AA, BA ASTM D2000/SAE J200 Type, Class: HK Apple Compound Designation: SB Apple Compound Designation: AF Standard Color: Black Standard Color: Black Description: Also known as Buna S, or GR-S (Government Rubber-Styrene), Styrene Butadiene was Description: A copolymer of tetrafluoroethylene/ the elastomer substituted for Natural Rubber during propylene, TFE/P can offer a combination of high World War II. Compounded properties are similar to temperature and chemical resistance. those of Natural Rubber. Key Use(s): Seals for oil field, aerospace, chemical Key Use(s): Isolation dampeners. and general industrial environments. Temperature Range: Standard Compound: Temperature Range: Standard Compound: +14°F -50°F to +212°F. (Dry Heat Only) to +446°F. Hardness (Shore A): 40 to 90. Hardness (Shore A): 60 to 90. Features: The main use for Styrene Butadiene today Features: Resistance to a wide range of chemicals, is in the manufacture of automobile . high temperature and electrical capabilities give broad application diversity. TFE/P have resistance to acids Limitations: SBR is not recommended for exposure and bases, steam/hot water, corrosion inhibitors, oils to petroleum oils, most hydrocarbons, strong acids, and lubricants, and industrial solvents. TFE/P also or ozone. offer improved low temperature properties over most This material is seldom used in modern sealing fluoroelastomers. applications. It has been replaced by better performing Limitations: Tests have shown that other FKM materials. elastomers are recommended for automotive fuels since they have less volume swell than TFE/P. Also, TFE/P has shown to have less than desirable results when exposed to toluene, ethers, ketones, and acetic acid.

Rule You must test all seals in their actual environment of Thumb because every application is unique.

71 www.applerubber.com 1.800.828.7745 (US & Canada Only) • +1.716.684.6560 (International) Limitations: The physical properties of thermoplastic Thermoplastic Elastomers elastomers are highly dependent upon the properties Description: Thermoplastic elastomers combine of the and elastomeric regions of the copolymer. the processing advantages of plastics with the rubber- Consequently, as temperature changes, so does like performance of elastomers. Known as two-phase the behavior of the TPE. The low temperature limit systems, these copolymers are comprised of both hard is defined by the glass transition temperature of the (plastic) and soft (elastomeric) molecular regions, with rubber phase, below which the material is brittle. each region contributing advantages and limitations to Likewise, the high temperature limit is defined by the the final material performance. Chemically, fully-cured melting point of the plastic phase, above which the thermoset rubber particles are dispersed throughout material softens and begins to flow. This results in a continuous thermoplastic matrix. Examples of this lowering the overall heat resistance of the copolymer. class of material are Santoprene® and Geolast® from Advanced Elastomer System (AES) and Dynaflex™ Also, as temperature increases, compression set from GLS Corporation. increases which limits the overall component size and complexity due to stack-up tolerances. Likewise, the Key Use(s): A broad range of applications that chemical resistance of the thermoplastic is determined 6 spans from bumpers to bellows, vibrational dampers, by the limits of BOTH materials comprising the system. couplers, and grommets. Also used throughout the automotive, major and small appliances, and aerospace industries. Features: In virtually all cases, the substitution of these materials for traditional thermosetting materials results in such benefits as significantly increased production speeds (via conventional plastic injection molding machines) and the ability to reuse clean scrap without a loss in physical properties. This results in a reduced part cost due to minimized scrap loss. Please Note the Following: Also, they are available in a broad range of durometers ! and colors and, by adjusting the percentage of The applications, suggestions and recommendations hard (plastic) segments in the copolymer matrix, the contained in this book are meant to be used as a professional guide only. Because no two situations or installations are the physical properties can be modified. For example, as same, these comments, sug­gestions, and recommendations are styrene content is increased in polystyrene elastomer necessarily general AND SHOULD NOT BE RELIED UPON BY block copolymers, they change from weak rubber-like ANY PUR­CHASER WITHOUT INDEPENDENT VERIFICATION materials to strong elastomers, to leathery materials, to BASED ON THE PARTICULAR INSTALLATION OR USE. We finally hard, glass-like products (with styrene content strongly recom­mend that the seal you select be rigorously tested in the actual application prior to production use. above 75%).

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® General Properties Of O-Ring Elastomers

Ester (Skydro Ester Polar Solvents (keytones) Solvents Polar F F E E P P P P P P P P P P P P G

F-G F-G Phosphate Phosphate E E P P P P P P P P P P P P P G G

F-P F-P Halogenated Hydrocarbons Halogenated E P P P P P P P P P P P

F-P F-P F-P F-P F-P F-G G-E Aromatic Hydrocarbons Aromatic F E E E E P P P P P P P P G

F-P F-P F-G F-G F-G Aliphatic Hydrocarbons Aliphatic

F F F E E E E Petroleum Based Petroleum P P P P P G G G

F-G

Lubricating Oils Lubricating G-E G-E G-E

F E E E E E E P P P P P G G G G G Alcohols F-G G-E

F E E E E E E E P P G G G Alkali Resistance, Conc. Resistance, Alkali F-G G-E G-E G-E G-E G-E

F E E P P P P P P G G Acid Resistance, Conc. Resistance, Acid F-E F-E F-G F-G G-E G-E P-G P-G

F E E E E P P P P G G G Gas Impermeability Gas F-G F-G F-G F-G F-G P-G P-G

F E E

P P P

G G G

F ˚ Steam Resistance Under 300 Under Resistance Steam F-P F-G G-E G-E G-E G-E G-E G-E G-E G-E

F E E E E P P P P P P P P P P P P G Water Swell Resistance Swell Water F-P

E E E E E E E P P P G G G G G G Ozone Resistance Ozone F-G F-G F-G

E E E E E E E E E P P P G G G G G Weather Resistance Weather G-E G-E

E E E E E E E E E P G G G G Tear Resistance Tear P-F G-E G-E G-E G-E

F F E E E E E P P P G G G G G Abrasion Resistance Abrasion P-F F-G F-G F-G

E E E P P P G G G G G Adhesion To Metals To Adhesion F-G F-G G-E G-E G-E G-E P-G P-G

F E E E P P G G G G Compression Set Compression F-P F-G F-G F-G F-G G-E G-E G-E

F P G G G G G G G Resilience-Rebound F-G F-G F-G F-G G-E G-E G-E G-E G-E P-G

G

F F F E P P P G G G G Shore A Shore

F-G F-G F-G

G-E

G-E

G

F

F-G

Hardness Range Hardness 98

5-80

Maximum (%) Maximum 70&90 40-95 55-90 40-9 0 40-90 40-90 50-90 30-90 50-8 0 40-80 60-90 50-90 40-90 50-90 65-90 40-90 40-90

Elongation

600 300 500 600 190 650 800 400 800 600 400 600 400 450 600 300 340 600 700

120 to Tensile Strength Tensile Blank =Information not available or conflicting

F F F F F F F E P P P G G G F-G F-G G-E G-E G-E

Temp. Limits °F Limits Temp.

Low/High -13 to +446 -40 to +275 -85 to +400 -30 to +175 -50 to +212 -40 to +275 -50 to +250 -25 to +300 -50 to +225 -30 to +175 -75 to +400 -13 to +338 -40 to +250 -13 to +600 -30 to +300 -58 to +158 -40 to +257

+14 to +446

-300 to +450 Economy

F F F F F F F E E E P P P P P P G G G

J200 Type, Class Type, J200

D2000/SAE ASTM HK CA; DA AA; BA; BG CH AA; BA DF; DH AK; BK ▲ FK EG FC; FE; HK EG AA; BA EE; EF; BC; BE ▲ GE KK DH AA BK; CH BF; BG:

▲ =No designation at time of publication

Designation

D1418 ASTM P =Poor

FKM EPM; EPDM AU; EU CO; ECO IIR ACM T ▲ FVMQ MQ; PMQ FKM SBR AEM CR FEP VMQ; PVMQ FFKM HNBR NR NBR; XNBR

Designation Apple Material Material Apple

F =Fair TF VT ZT SL VA FS AF EP PY TH KA EH SB CP NA BU CR BN MP

)

® ) ) ®

®

G =Good

)

® Elastomers ) , Chemraz ® ®

73

Fluorocarbon Polyacrylate Fluorosilicone Ethylene-Propylene Millable Silicone Tetrafluoroethylene/ Cast Polyurethane,

Epichlorohydrin Butyl Polyurethane,

Styrene Styrene Butadiene Ethylene Acrylic Chloroprene Polytetrafluoro- ethylene (Teflon Natural Rubber Propylene Propylene (Aflas (Vamac (Neoprene Hydrogenated Perfluoroelastome (Kalrez

Nitrile, Nitrile (Buna-N) Polysulfide E =Excellent Common Military Specifications

AMS (Aerospace Material Specifications) (1) Dash numbers correspond with the AN (Air Force/Navy Specifications) AS-568B dash numbers M;MIL;MS (Military Specifications) (2) Dash numbers correspond with the NAS (National Aeronautical Specifications) 900 tube fitting series Material Numbering Durometer Base Temp. Description Specification Series (+/-5) Polymer Range (°F) AMS3209 N/A 70 Neoprene -40 to +225 Weather Resistant AMS3301 N/A 40 Silicone -85 to +400 General Purpose AMS3302 N/A 50 Silicone -85 to +400 General Purpose AMS3303 N/A 60 Silicone -85 to +400 General Purpose AMS3304 MS9068 (1) 70 Silicone -85 to +400 General Purpose AMS3305 N/A 80 Silicone -85 to +400 General Purpose AMS7271 MS9020 (2) 65 Nitrile -67 to +300 Phosphate Ester Resistant MS9021 (1) AMS7277 N/A 70-85 Butyl -85 to +400 General purpose MIL-P-5315 MS29512 (2) 70 Nitrile -65 to +200 Hydrocarbon Fuel Resistant MS29513 (1) MIL-P-5510 MS28778 (2) 90 Nitrile -65 to +212 For Hydraulic Fluid Systems MIL-P-5516 AN6227 70 Nitrile -65 to +275 Hydraulic Fluids AN6230 MIL-H-5606 MIL-R-7362 MS29561 (1) 70 Nitrile -65 to +250 For MIL-L-7808 Fluids NAS617 (2) 6 MIL-P-25732 MS28775 (1) 70 Nitrile -65 to +275 For Hydraulic Fluid Systems MIL-R-83248 Type 1, Class 1 M83248/1 (1) 75 Fluorocarbon -20 to +400 High Temperature, Fluid & Type 1, Class 2 M83248/2 (1) 90 Fluorocarbon -20 to +400 Compression Set Resistance MIL-R-25988 Class 1, Grade 70 M25988/1 (1) 70 Fluorosilicone -80 to +350 Oil & Fuel Resistant Class 1, Grade 60 M25988/3 (1) 60 Fluorosilicone -80 to +350 Oil & Fuel Resistant Class 1, Grade 80 M25988/4 (1) 80 Fluorosilicone -80 to +350 Oil & Fuel Resistant ZZR-765B Class 1A & 1B High Temperature & Grade 40 N/A 40 Silicone -80 to +437 Low Compression Set Resistant Grade 50 N/A 50 Silicone -103 to +437 High & Low Temperature Resistant & Low Compression Set Resistant Grade 60 N/A 60 Silicone -103 to +437 Same As Above Grade 70 N/A 70 Silicone -103 to +437 Low Temperature & Low Compression Set Resistant ZZR-765B Class 2A & 2B High Temperature & Grade 40 N/A 40 Silicone -80 to +437 Low Compression Set Resistant Grade 50 N/A 50 Silicone -103 to +437 High & Low Temperature Resistant & Low Compression Set Resistant Grade 70 N/A 70 Silicone -80 to +437 Low Temperature & Low Compression Set Resistant Grade 80 N/A 80 Silicone -80 to +437 Same As Above ZZR-765B Class 2A High & Low Temperature Resistant & Grade 60 N/A 60 Silicone -103 to +437 Low Compression Set Resistant ZZR-765B Class 2B High Temperature Resistant & Grade 60 N/A 60 Silicone -80 to +437 Low Compression Set Resistant ZZR-765B Class 3B Grade 70 N/A 70 Silicone -94 to +392 Tear & Flex Resistant Grade 80 N/A 80 Silicone -94 to +392 Same As Above Note: For most current specifications, visit our website.

www.applerubber.com 74 1.800.828.7745 (US & Canada Only) • +1.716.684.6560 (International)