Mechanical seal selection

 O -ring material classification control and advantages and disadvantages: 

    

 1. Natural rubber NR 

   

    

    (Natural Rubber) is made of rubber tree-collecting latex and is a polymer of isoprene. Has good wear resistance, high elasticity, tear strength and elongation. It is easy to age in the air, becomes sticky when exposed to heat, easily swells and dissolves in mineral oil or gasoline, and is resistant to alkali but not strong acid. • It is a raw material for making tapes, hoses, and rubber shoes, and is suitable for making shock-absorbing parts, products used in automotive brake fluids, and alcohol-containing liquids such as ethanol.   

    

 2. SBR, SBR 

 

    (Styrene Butadiene Copolyme) A copolymer of butadiene and styrene. Compared with natural rubber, it has uniform quality and less foreign matter, but its mechanical strength is weak. It can be blended with natural rubber.   

    advantage: 

    • Low cost non-oil resistant material   

    • Good water resistance, hardness of 70 or less with good elasticity   

    • Poor compression at high hardness歪   

    • Can use most neutral chemicals and dry and toxic organic ketones   

    Disadvantages:   

    • It is not recommended to use strong acids, ozone, oils, oil esters and fats, and most of the hydrocarbons. • widely used in the tire industry, footwear,? Cloth industry and conveyor industries.   

    

 3. Butyl rubber IIR 

 

    (Butyl Rubber) is a mixture of isobutylene and a small amount of isoprenes . It has a small amount of unsaturated groups for sulfur. Because the steric hindrance of methyl groups is less than other polymers, the gas permeability is less, and it is hot. Sunlight, ozone resistance is great, electrical insulation is good; resistance to polar solvents such as alcohols, ketones, esters, etc., the general temperature range is -54~  110 °C  .   

    advantage:   

    • Impervious to most general gases   

    • Good resistance to sunlight and ozone   

    • Can be exposed to animal or vegetable oils or oxidizable chemicals   

    Disadvantages:   

    • Not defined with petroleum solvents, coal kerosene and aromatic hydrogen. • Used to make rubber parts for chemical resistant and vacuum equipment.   

    

 4. Hydrogenated butadiene rubber HNBR 

 

    (Hydrogenate Nitrile) hydrogenated butyl rubber is a part of double-stranded by hydrogenation in the butyl rubber. After hydrogenation, its temperature resistance and weather resistance are much higher than that of ordinary butyl rubber. The oil resistance is similar to that of ordinary butyl rubber. The general temperature range is -25~  150 °C  .   

    advantage:   

    • Better anti-wear properties than Dingjiao   

    • Excellent resistance to corrosion, tensile, tear and compression   

    • Good resistance to ozone, sunlight and other atmospheric conditions   

    • Generally suitable for use in laundry or dishwashing detergents   

    Disadvantages:   

    • Not recommended for use in alcohols, esters or aromatic solutions. • Air-conditioning and refrigeration industry, widely used in environmentally friendly refrigerants R  134a  Seals in the system.   

    • Automotive engine system seals.   

    

 5. Ethylene propylene rubber EPDM 

 

    

    (Ethylene propylene rubber) is a copolymer of ethylene and propylene, and its main chain is not double-stranded. Therefore, it is excellent in heat resistance, aging resistance, ozone resistance, and stability, but sulfur vulcanization is not possible. In order to solve this problem, a small amount of a double-stranded third component is introduced into the EP main chain, and sulfur and sulfur can be used to form EPDM . The general temperature range is -50~  150 °C  . Excellent resistance to polar solvents such as alcohols, ketones, glycols and phosphates.   

    advantage: 

    • Good weather resistance and ozone resistance 

    • Excellent water and chemical resistance   

    • Alcohols and ketones can be used   

    • High temperature resistant steam, good impermeability to gases   

    Disadvantages:   

    • Not recommended for food use or exposure to aromatic hydrogen. • Seals for high temperature steam environments.   

    • Sanitary equipment seals or parts.   

    • Brake ( brake ) rubber parts in the system.   

    • Seals in radiators ( car tanks ) .   

    

 6. Butadiene rubber NBR 

 

    

    (Nitrile Rubber) is a copolymer of acrylonitrile and butadiene. The content of acrylonitrile is 18%~50% . The higher the acrylonitrile content, the better the resistance to fossil fuel hydrocarbon fuel oil, but the low temperature performance. Variation, the general temperature range is -25~  100 °C  . Butadiene rubber is one of the most commonly used rubbers for oil seals and O -rings.   

    advantage:   

    • Has good oil, water, solvent and high pressure resistant properties.   

    • Has good compression, abrasion and elongation.   

    Disadvantages:   

    • Not suitable for use in polar solvents such as ketones, ozone, nitrohydrocarbons, MEK and chloroform. • Used to make fuel tanks, oil tanks, and rubber parts used in fluid media such as petroleum hydraulic oil, gasoline, water, silicone grease, silicone oil, diester lubricating oil, glycol hydraulic oil, etc., especially sealing parts. . It can be said that it is the most widely used and lowest cost rubber seal.   

    

 7. Neoprene CR 

 

     

    (Neoprene , Polychloroprene) is a polymer of chlorobutene monomers. The rubber after vulcanization has good elastic wear resistance, is not afraid of direct sunlight, has good atmospheric weathering resistance, is not afraid of intense distortion, is not afraid of refrigerant such as dichlorodifluoromethane and ammonia, and is resistant to dilute acid and silicon ester resistance. Lubricating oil, but not resistant to phosphate ester hydraulic oil. It is easy to crystallize and harden at low temperature, has poor storage stability, and has a large expansion amount in mineral oil with low aniline point. The general temperature range is -50~  150 °C    

    advantage:   

    • Good elasticity and good compression set.   

    • The formula does not contain sulfur and is therefore very easy to make   

    • With anti-animal and vegetable oil properties   

    • Will not affect physical properties due to neutral chemicals, fats, greases, various oils, solvents 

    • With flameproof properties   

    Disadvantages:   

    • It is not recommended to use chemicals such as strong acids, nitrohydrocarbons, esters, chloroforms and ketones. • Seals resistant to R12 refrigerants. • Rubber parts or seals on household appliances. 

    • Suitable for making a variety of parts that are in direct contact with the atmosphere, sunlight, and ozone.   

    • Suitable for all kinds of flame resistant and chemical resistant rubber products.   

    

 8. Chlorosulfonated polyethylene glue CSM 

 

    (Hypalon , Polyethylene) Chlorosulfonated polyethylene is a DuPont patented synthetic rubber. Heat resistance, weather resistance, ozone resistance are good; acid resistance is also good, often used in oxidation resistant chemicals ( nitric acid, sulfuric acid ) , the general temperature range is -45~  120 °C  .   

    advantage:   

    • Good resistance to ozone, oxidation and flame   

    • Physical properties similar to neoprene and have better acid resistance   

    • Excellent abrasion resistance   

    • Has the same low friction surface as the rubber   

    • Resistance to oils and solvents is between butyl rubber and neoprene   

    • It is recommended to use water to prevent leakage   

    Disadvantages:   

    • Exposure to concentrated oxidizing acids, nitrohydrocarbons, esters, ketones and fragrant hydrogen is not recommended.   

    

 9. Silicone rubber SI 

 

     

    (Silicone Rubber) The silica gel backbone is a combination of silicon (-si-o-si) . It has excellent heat resistance, cold resistance, ozone resistance and weather resistance. Has good electrical insulation properties. The tensile strength is inferior to ordinary rubber and does not have oil resistance. advantage:   

    • Tensile strength up to 1500PSI and resistance to tearing after modulation  88LBS 

    • Good elasticity and good compression歪   

    • Good resistance to neutral solvents   

    • Excellent heat resistance   

    • Excellent cold resistance   

    • Excellent resistance to ozone and oxide attack   

    • Excellent electrical insulation properties   

    • Insulation and heat dissipation   

    Disadvantages:   

    • Not recommended for use in most concentrated solvents, oils, concentrated acids and diluted sodium hydroxide. • Seals or rubber parts used in the household appliance industry, such as electric kettles, electric irons, and rubber parts in microwave ovens.   

    • Seals or rubber parts in the electronics industry, such as cell phone buttons, cushions in DVDs , seals in cable glands, etc.   

    • Seals on various types of articles that come into contact with the human body, such as water bottles, water dispensers, etc.   

    

 10. Silicone Fluoride Rubber FLS 

 

     

    (Fluorinated Silicone Rubber) Silicone fluororubber is a fluorinated silicone rubber. Its general properties have the advantages of fluororubber and silicone rubber. It is excellent in oil resistance, solvent resistance, fuel oil resistance and high and low temperature resistance. For -50~  200 °C  .   

    advantage:   

    • Suitable for special applications such as corrosion resistance to oxygen-containing chemicals, aromatic hydrogen-containing solvents and chlorine-containing solvents.   

    Disadvantages:   

    • It is not recommended to be exposed to brake oil, ketones and hydrazine solutions. • Spacecraft.   

    

 11. Fluororubber FPM 

 

     

    (Fluoro Carbon Rubber) The fluorine-containing rubber in the molecule has various types depending on the fluorine content ( i.e., monomer structure ) . The currently widely used hexafluoride fluororubber was first marketed by DuPont under the trade name "Viton" . High temperature resistance is superior to silicone rubber. It has excellent chemical resistance, most oils and solvents ( except ketones and esters ) , weather resistance and ozone resistance. Cold resistance is poor. The general temperature range is -20. ~  250 °C  . Special formula can withstand low temperature to    -40 °C  . advantage:   

    • can resist heat to    250 °C    

    • Ability to resist most oils and solvents, especially all acids, aliphatic hydrocarbons, aromatic hydrocarbons and animal and vegetable oils   

    Disadvantages:   

    • Not recommended for ketones, low molecular weight esters and mixtures containing nitrates. • Automotive, locomotive, diesel engines and fuel systems.   

    • Chemical plant seals.   

    

 12. Perfluoroelastomer FFPM 

 

    

    (Perfluoroelastomer) 

    advantage:   

    • Optimal heat resistance 

    • Excellent chemical resistance   

    • Low Outgassing features   

    • Excellent anti- Plasma characteristics   

    Disadvantages:   

    • Poor temperature resistance 

    • Higher raw material prices   

    • • perfluoro difficult to produce a high range of products widely used in the semiconductor industry and related industries, the use of the information, the operating range of the manufacturing process a thin film comprising PVC, CVD and etching processes and various high-vacuum sealing process. 

    

 13. Acrylate rubber ACM 

 

    

    (Polyacrylate Rubber) Alkyl Ester Acrylate dominated by polymerization of the elastomeric component, the oil and petrochemical resistant, temperature, weather resistance are good in mechanical strength, deformation rate and water resistance is less, than the average oil plastic slightly difference. The general temperature range is -25~  170 °C  .   

    advantage:   

    • Suitable for use in automotive transmission oil   

    • Has good resistance to oxidation and weathering   

    • Features with anti-bending variants   

    • Excellent resistance to oil   

    • Suitable for use in automotive transmission systems and power steering   

    Disadvantages:   

    • Not suitable for hot water   

    • Not suitable for use in brake oil   

    • Does not have low temperature resistance   

    • Not suitable for use in phosphate esters • Automotive transmission systems and power system seals.   

    

 Tags: mechanical seal O-ring seal