Solenoid valve sealing materials are currently three of the most commonly used.
NBR rubber
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, strong adhesion. Its disadvantages are poor low temperature resistance, poor ozone resistance, poor electrical performance, slightly lower elasticity.
In addition, it also has good water resistance, air tightness and excellent bonding properties. Widely used in making a variety of oil-resistant rubber products, a variety of oil-resistant gaskets, gaskets, sleeves, flexible packaging, soft rubber hose, printing and dyeing cots, cable rubber materials, etc., in the automobile, aviation, petroleum, copying and other industries become essential elastic materials.
Nitrile butadiene 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 hydrocarbon, ketone and ester solvents, and is not suitable for insulation.
Main use
Nitrile rubber is mainly used in the production of oil-resistant products, such as tubing, tape, rubber diaphragm and large oil capsule, often used in the production of all kinds of oil-resistant molding products, such as O-ring, oil seal, bowl, diaphragm, valve, bellows, and also used in the production of rubber plate and wear-resistant parts.
EPDM ethylene propylene diene rubber
Epdm is a terpolymer of ethylene, propylene and unconjugated diolefin, which began commercial production in 1963. Worldwide consumption is 800,000 tons per year. The most important characteristic of EPDM is its excellent oxidation resistance, ozone resistance and erosion resistance. Because EPDM belongs to polyolefin family, it has excellent vulcanization characteristics. Among all rubbers, EPDM has the lowest specific gravity. It can absorb a large amount of fillers and oils without affecting characteristics. So you can make cheap rubber compounds.
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 one is not going to be the main chain, it's just going to be the side chain. The main polymer chain of epDM is completely saturated. This property makes EPDM resistant to heat, light, oxygen and, above all, ozone. Ethylene propylene diene is essentially non-polar, resistant to polar solutions and chemicals, has low water absorption, and has good insulation properties.
characteristic
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. Elasticity;
8. Adhesion.
VITON Fluorine Rubber (FKM)
Rubber whose molecules contain fluorine are of various types according to fluorine content or monomer structure; Fluorinated rubber has better high temperature resistance than silicone rubber, chemical resistance, resistance to most oils and solvents (except ketones and esters), good weather resistance, ozone resistance, but poor cold resistance; Generally widely used in steam cars, B products, chemical plant seals, the use of temperature range -20℃ ~ 260℃, low temperature requirements when the use of low temperature resistance type can be used to -40℃, but the price is higher.
