How to choose the sealing material of the solenoid valve?

There are three commonly used sealing materials for solenoid valves.

NBR nitrile rubber

It is prepared by emulsion polymerization of butadiene and acrylonitrile. Nitrile rubber is mainly produced by low temperature emulsion polymerization. It has excellent oil resistance, high wear resistance, good heat resistance and strong adhesion. The 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. It is widely used in the manufacture of various oil-resistant rubber products, various oil-resistant gaskets, gaskets, casings, flexible packaging, soft rubber hoses, printing and dyeing rubber rollers, cable rubber materials, etc. Material.

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

The main purpose of the solenoid valve

Nitrile rubber is mainly used to make oil-resistant products, such as oil-resistant pipes, tapes, rubber diaphragms and large oil bladders. etc., also used to make rubber sheets and wear-resistant parts.

EPDM EPDM rubber

EPDM rubber is a terpolymer of ethylene, propylene, and non-conjugated dienes, and commercial production began in 1963. Annual worldwide consumption is 800,000 tons. The main characteristic of EPDM is its excellent resistance to oxidation, ozone and erosion. Since EPDM belongs to the polyolefin family, it has excellent vulcanization characteristics. Among all rubbers, EPDM has a very low specific gravity. It can absorb large amounts of fillers and oils with little effect on properties. Therefore, a low-cost rubber compound can be produced.

Molecular structure and properties: EPDM is a terpolymer of ethylene, propylene and non-conjugated dienes. Diolefins have a special structure, only one of the two bonds can be copolymerized, and the unsaturated double bonds are mainly used as cross-links. The other unsaturated one will not become the polymer backbone, only the side chains. The main polymer chain of EPDM is fully saturated. This property makes EPDM resistant to heat, light, oxygen, and especially ozone. EPDM is nonpolar in nature, resistant to polar solutions and chemicals, has low water absorption, and has good insulating properties.

Solenoid valve features:

1. Low density and high filling;

2. Aging resistance;

3. Corrosion resistance;

4. Water vapor resistance;

5. Resistance to superheated water;

6. Electrical performance;

7. Elasticity;

8. Adhesion.

VITON Fluorine Rubber (FKM)

The fluorine-containing rubber in the molecule has various types according to the fluorine content, that is, the monomer structure; the high temperature resistance of hexafluoride fluorine rubber is better than that of silicone rubber, chemical resistance, resistance to most oils and solvents (ketones, esters) Except for), good weather resistance and ozone resistance, but poor cold resistance; generally widely used in automobiles, B and other products, and seals in chemical plants, the operating temperature range is -20 ° C ~ 260 ° C, and there are The low temperature resistant type can be used up to -40℃, but the price is higher.