Solenoid valve commonly used three kinds of sealing materials

Solenoid valve commonly used three kinds of sealing materials

NBR rubber (nitrilebutadienerubber)

Made of butadiene and acrylonitrile by emulsion polymerization, nitrile rubber is mainly produced by low temperature emulsion polymerization, excellent oil resistance, high wear resistance, good heat resistance and strong adhesion. Its disadvantages are poor low temperature resistance, poor ozone resistance, poor electrical properties, and slightly lower elasticity.

In addition, it also has good water resistance, air tightness and excellent bonding properties. Widely used in the production of a variety of oil-resistant rubber products, a variety of oil-resistant gaskets, gaskets, bushings, flexible packaging, soft hose, printing and dyeing roller, cable rubber materials, etc., in the automotive, aviation, petroleum, copying and other industries to become an essential elastic material.

Nitrile rubber has excellent oil resistance, its oil resistance is second only to polysulfide rubber and fluorine rubber, and has wear resistance and air tightness. The disadvantage of butadiene rubber is that it is not resistant to ozone and aromatic, halogenated hydrocarbons, ketones and ester solvents, and is not suitable for insulating materials.

Main use

Nitrile rubber is mainly used in the production of oil-resistant products, such as tubing, tape, rubber diaphragm and large oil capsule, etc., often used in the production of various oil-resistant molded products, such as O-rings, oil seals, leather bowls, diaphragms, valves, bellows, etc., and also used in the production of rubber plates and wear-resistant parts.

EPDM Ethylene Propylene DieneMonomer

Ethylene propylene diene (EPDM) rubber is a terpolymer of ethylene, propylene and non-conjugated diolefin, which began commercial production in 1963. Worldwide consumption is 800,000 tons per year. The main characteristics of EPDM are its superior oxidation resistance, ozone resistance and erosion resistance. Epdm rubber belongs to the polyolefin family, it has excellent vulcanization characteristics. Among all rubbers, EPDM has a low specific gravity. It can absorb a lot of fillers and oil without affecting the characteristics. This makes it possible to make rubber compounds at low cost.

Molecular structure and properties

Epdm is a terpolymer of ethylene, propylene and unconjugated diolefin. Diolefin has a special structure, only one of the two bonds can copolymerize, and the unsaturated double bond is mainly used as the cross-chain. The other unsaturated one will not become the main chain of the polymerization, it will only become the side chain. The main polymer chain of EPDM is completely saturated. This property makes EPDM resistant to heat, light, oxygen, and especially ozone. Epdm is essentially non-polar, resistant to polar solutions and chemicals, has low water absorption, and has good insulation properties.

Features:

1, low density and high filling; 2, aging resistance; 3, corrosion resistance; 4, water steam resistance; 5. Resistance to excessive hot water; 6, electrical performance; 7. Flexibility; 8. Adhesion.

VITON (FKM)

The rubber whose molecule contains fluorine has various types according to the fluorine content, that is, the monomer structure; At present, the widely used fluorinated rubber of the hexafluoride system has been listed by the DuPont Company under the trade name "VITON". High temperature resistance is better than silicone rubber...... Chemical resistance, resistance to most oils and solvents (except ketones and esters), weather resistance, ozone resistance are good, but cold resistance is poor; Generally widely used in turbine cars, B and other products, chemical plant seals, the use of temperature range -20 ° C ~ 260 ° C, low temperature requirements when using low temperature can be selected to apply to -40 ° C, the price is higher.