Advantages of using fluorine rubber O ring
1, chemical stability: fluorine rubber has high chemical stability, is one of the best dielectric properties of all elastomers. 26 type fluorine rubber is resistant to petroleum based oils, diester oils, silicon ether oils, silicic acid oils, inorganic acids resistant, most organic, inorganic solvents, pharmaceuticals and so on, only low molecular ketone, ether, ester, amine, ammonia, hydrofluoric acid, phosphoric acid hydraulic oil. The dielectric properties of type 23 fluoro rubber are similar to those of type 26, and are more unique. The oxidation resistance of inorganic acids such as fuming nitric acid and concentrated sulfuric acid is better than that of type 26. At 98% HNO3 in room temperature, the volume expansion is only 13%~15% for 27 days.
2, high temperature resistance: fluorine rubber high temperature resistance and silicone rubber, it can be said to be the best elastomer in the present. 26-41 fluorine rubber can be used for 26-41 years at a temperature of 250 degrees, a short term use at 300 degrees, 246 fluorine heat resistance ratio is better. Still maintain good elasticity. Type 23-11 fluoride gel can be used for 250 years at a temperature of 200 degrees and used for a short period of time.
3, good aging resistance: fluorine rubber has excellent resistance to weather aging, ozone resistance. It is reported that the VitonA developed by DuPont is still satisfactory after ten years of natural storage, and there is no obvious crack in the air with ozone concentration of 0.01% for 45 days. 23 type fluorine rubber has excellent weather resistance and ozone resistance.
4, excellent vacuum performance: type 26 fluorine rubber has excellent vacuum performance. The vacuum outgassing rate of vulcanizate with 246 fluorine rubber basic formula is only 37 x 10-6 Torr / sec. Cm 2. 246 type fluorine rubber has been successfully applied under vacuum condition of 10-9 torr.
5, excellent mechanical properties: fluorine rubber has excellent physical and mechanical properties. In general, compression permanent deformation large fluorine rubber under high temperature, but if in the same conditions, such as from the same time compression at 150 DEG C and D of chloroprene rubber than type 26 to type 26 fluorine rubber, fluorine rubber as rubber at 150 DEG C than x 24 hours compression deformation at 200 DEG C x 24 hours under compression deformation.
6. Good electrical properties: 23 type fluorine rubber has good electrical properties, moisture absorption is lower than other elastomers, it can be used as a good electrical insulation material. Type 26 rubber can be used at low frequency and low pressure.
7, permeability is small: fluorine rubber solubility of gas is relatively large, but the diffusion rate is relatively small, so the overall permeability is also small. It is reported that the permeability of type 26 fluorine rubber to oxygen, nitrogen, helium, carbon dioxide gas at 30 C is comparable to that of butyl rubber and butyl rubber, better than neoprene and natural rubber.
Sealing mechanism of hydraulic rubber seals (O type ring)
The sealing mechanism of the seal involves two factors, one is the sealing of the cavity, mainly the positioning of the outer part of the seal (static parts) in the cavity; the two is the dynamic sealing of the sealing lip and the surface of the rotating shaft, which is the most important function of the seal O ring.
The sealing mechanism of the sealing lip contact area of the sealing ring O is of great importance to the sealing function of the seal. It depends on the design of the sealing lip, the structure of the elastic material and the roughness of the surface. The radial force of seal lip, the design of sealing lip angle and the design of the distance between lip tip and spring center produce a contact pressure which is asymmetrical to the axis surface: the pressure on the oil side is larger and rises steeply; the air side pressure is small angle attenuation. The amount of interference (inner diameter of the sealing lip in the free state, no load conditions for the shaft diameter slightly smaller than) complexes, the asymmetric distribution of the contact pressure, the combined effect of generating and rotating shaft circumference of the annular hoop stress, resulting in deformation of structural characteristics of lip seal contact area. The deformation structure of the sealing elastomer is formed during the test run of the oil seal, and plays a decisive role in the sealing performance. Therefore, the seal type O ring needs a running in period of test run. The influence of the helix and the rotation of the shaft results in the pumping effect to the oil side from the deformation structure.
The friction characteristics of the seal face of the seal ring of O ring are governed by the viscosity and sliding velocity of the fluid, and there is an oil film on the sliding surface. The sliding surface between the O ring and the shaft of the seal moves under the lubrication condition of the oil film separation, so the friction force is small and the wear is less. The flow of oil on the sliding contact surface of the O ring of the seal is the circulation from the atmosphere side to the oil side and from the oil side to the atmosphere side. The sliding surface is well lubricated and prevents wear and tear, so there is no leakage. Visible, the oil seal lip, lip material, lip shape of these two factors for subtle control, thereby affecting the seal O ring lubrication characteristics and sealing principle, is crucial.
How to distinguish three yuan ethylene propylene O type ring and fluorine rubber O type ring?
Three yuan EPDM rubber O ring and fluorine rubber O type ring are black, put together, it is not see which is fluorine rubber O type ring. Taiwan Bo Jie Sealing Technology Development Co., Ltd. teach you two points to identify:
, 1 by weight of special is not the same as the fluorine rubber O ring density in about 1.9, while the three rubber O ring density in about 1.2.
2, from the burning time can also identify, fluorine rubber O ring burning from fire, will automatically turn off. And three EPDM O ring will not automatically flameout, will continue to burn.
From the above 2 points of view, three Yuan rubber O ring with fluorine rubber O ring has a significant performance difference, can be clearly distinguished. If the two colors are different, they are easier to distinguish.
Taiwan
Why should fluorine rubber compound be parked?
1, in the mixing process, rubber macromolecular chain by rubber mechanical shear force, tear force, friction and so on to clear, so that the rubber macromolecular chain is in a relatively stable state, prevent after vulcanization deformation, shrinkage;
2. Make all kinds of additives disperse more evenly in rubber, further penetrate into the big chain of rubber, absorb, affinity, absorb, form more gel (contain rubber) with rubber macromolecule chain, and improve the reinforcing effect to rubber;
3. Make the rubber mixture from rough to hard, become flexible, liquidity, reduce the shrinkage and appearance defects of finished products;
4, the use of mixed rubber parking, you can quickly check the physical properties to see whether the mixed rubber reachedExpected physical index requirements. If some indexes are not qualified (such as plasticity, hardness, etc.), supplementary mixing can be carried out to prevent unnecessary losses caused by mixing directly into the production process