Which material is better for O-rings? This is because many customers do not know what material O-rings should be used for their machinery. In fact, this is easy to do:

1.Natural rubber NR

(Natural Rubber) is made from latex collected from rubber trees and is a polymer of isoprene. It 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 expands 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. It is also suitable for making shock-absorbing parts and products used in liquids containing hydroxide radicals such as automobile brake fluid and ethanol.

2.Styrene-butadiene rubber S B R

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

advantage:

• Low cost non-oil resistant material

• Good water resistance, hardness below 70 with good elasticity

• Poor compression deflection at high hardness

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

shortcoming:

• It is not recommended to use strong acids, ozone, oils, esters, fats and most hydrocarbons. • Widely used in tire industry, shoe industry, cloth industry and conveyor belt industry.

3.Butyl rubber IIR

(Butyl Rubber) is the polymerization of isobutylene and a small amount of isoprenes. It retains a small amount of unsaturated groups for sulfur addition. Because the methyl group has less steric hindrance to the movement of molecules than other polymers, it has less gas permeability and is resistant to heat and It has high resistance to sunlight and ozone, and good electrical insulation; it has high resistance to polar solvents such as alcohols, ketones, and esters. The general operating temperature range is -54~110 ℃.

advantage:

• Impermeable to most common gases

• Good resistance to sunlight and ozone

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

shortcoming:

• Not recommended for simultaneous use with petroleum solvents, gum kerosene and aromatic hydrogen. • Used to make rubber parts resistant to chemicals and vacuum equipment.

4.Hydrogenated nitrile rubber HNBR

(Hydrogenate Nitrile) Hydrogenated nitrile rubber is a nitrile rubber that has been hydrogenated to remove part of the double chains. After hydrogenation, its temperature resistance and weather resistance are much higher than that of ordinary nitrile rubber, and its oil resistance is similar to that of ordinary nitrile rubber. The general operating temperature range is -25~150 ℃.

advantage:

• Better wear resistance than nitrile rubber

• Excellent corrosion resistance, tensile resistance, tear resistance and compression distortion properties

• Good resistance to ozone, sunlight and other atmospheric conditions

• Generally suitable for use in laundry or dishwashing detergents

shortcoming:

• Not recommended for use in alcohols, esters or aromatic solutions. • Air-conditioning and refrigeration industry, widely used as seals in environmentally friendly refrigerant R134a systems.

• Automotive engine system seals.

5. EPDM

(Ethylene propylene Rubber) is a copolymer of ethylene and propylene with no double-stranded main chain. Therefore, it has excellent heat resistance, aging resistance, ozone resistance, and stability, but it cannot be vulcanized with sulfur. In order to solve this problem, a small amount of a double-stranded third component is introduced into the EP main chain and sulfur is added to form EPDM. The general operating temperature range is -50~150°C. Excellent resistance to polar solvents such as alcohols, ketones, glycols and phosphate ester hydraulic oils.

advantage:

• Good weather resistance and ozone resistance

• Excellent water and chemical resistance

• Alcohols and ketones can be used

• Resistant to high temperature vapor and has good impermeability to gases

shortcoming:

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

• Plumbing fixture seals or parts.

• Rubber parts in brake (brake) systems.

• Seals in radiators (car radiators).

6.NBR

(Nitrile Rubber) is copolymerized by acrylonitrile and butadiene. The acrylonitrile content ranges from 18% to 50%. The higher the acrylonitrile content, the better the resistance to petrochemical hydrocarbon fuel oil, but the low temperature performance is Deterioration, the general operating temperature range is -25~100 ℃. NBR is one of the most commonly used rubbers for oil seals and O-rings.

advantage:

• It has good properties of oil resistance, water resistance, solvent resistance and high pressure oil resistance.

• It has good compression distortion, wear resistance and elongation strength.

shortcoming:

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