FKM is a synthetic polymer elastomer which contains fluorocarbon-based fluoroelastomer. Because of the fluorine atoms, FKM rubber offer an excellent heat resistance, antioxidant resistance, oil resistance, corrosion resistance and atmospheric aging resistance. It has been widely used in aerospace, aviation industry, automotive industry, oil gas and household appliances. FKM material plays a very important role in national defense industries.
Good Chemical Stability
FKM has a high degree of chemical stability, which is one of the best media resistant properties of all elastomers at present Type-26 FKMs can resistant to petroleum-based oils, diester oils, silicone ether oils, silicate oils, inorganic acids, most organic, inorganic solvents, pharmaceuticals, etc. In addition, it can resistant to low molecules of ketones, ethers, esters, amine, ammonia, hydrofluoric acid, chlorosulphate, phosphoric acid hydraulic oil. Type-23 FKMs are same with Type-26 FKMs in dielectric property, and it’s more unique, it has high resistance of strong oxidation inorganic acids like fuming nitric acid and concentrated sulfuric acid compared with Type-26 FKMs. When immersed in 98% HNO3 at room temperature for 27 days, the volume expansion is only 13% ~ 15%.
High Temperature Resistance
1.FKM has an excellent performance in high temperature resistance. It can be used in the temperature from 180 ℃ to 220 ℃ environment for a long time. If the temperature up to 250 ℃, it can be used in a short time, especially the Viton series produced by DuPont company, and its performance is superior in all aspects.
2.FKM has poor performance in low temperature, because of its chemical structure. The material formula and shape(thickness) play a important role in brittle temperature, if we increase the fillers in the formula, the brittle temperature will be destroyed sensitively, the thickness of the product increases, the brittle temperature also will be destroyed. But our company Shanghai HUAYI has experienced and professional engineer, they can design the formula to enhances the low temperature resistance of FKM.
FKM has excellent performance in weather aging resistance and ozone corrosion resistance. After 10 years of natural environment storage, the performance remained satisfactory. It has no significant cracking in the air with an ozone concentration of 0.01% for 45 days. Type-23 FKM has a good performance in weather aging resistance and ozone corrosion resistance.
Good Mechanical Properties.
FKM has excellent physical mechanical properties. Type-26 FKM normal working pressure is 10-30Mpa, the elongation at Break is 150-350%, and the tensile strength at Break is between 3 and 4KN/m. Type-23 FKM in the pressure 15-25Mpa, the elongation at break is 200%-600%, the tensile strength at break is between 2-7Mpa. Generally, the FKM featured greater permanent set in high temperature but if compared with the same conditions, such as the compression set at 150 ℃ for the same time, the compression set of butadiene rubber and chloroprene rubber is larger than that of Type-26 FKMs. The compression set of Type-26 FKMs at 200 ℃ for 24 hours is equivalent to that of butadiene rubber at 150 ℃ for 24 hours. SHANGHAI HUAYI engineer can design formula, modify materials and provide mechanical properties of materials through technical ways to make the material playing excellent physical properties.
Type-23 FKMs have great electrical properties, it has lower moisture absorption than other elastomers and can be used as a better electrical insulation material. Type-26 FKMs can be used at low frequency and low pressure.
Small Gas Permeability
The gas solubility of FKM is relatively large, but the diffusion speed is relatively small, so the overall permeability is also small. At 30 ℃, the permeability of Type-26 FKMs to oxygen, nitrogen, helium and carbon dioxide is same with that of butyl rubber and butadiene rubber, but it’s better than that of chloroprene rubber and natural rubber.
Radiation Resistance Properties
The radiation resistance of FKM is not good compared with other elastomers. After radiation, the Type-26 FKMs performed the crosslinking effect, while the Type-23 FKM performed the cracking effect. Under the condition of 1 × 107 Lun, the hardness increases by 1 ~ 3 degrees, the strength decreases by less than 20%, and the elongation decreases by 30% ~ 50%. Therefore, it is generally believed that Type-246 FKM can withstand 1 × 107 Lun, and the Maximum is 5 × 107 Lun.
Key and Practical Applications
Because FKM can offer an impressive range of chemical compatibility, high temperature resistance, oil resistance, high-vacuum and acid alkali resistance. With special available for specific application performance, making FKM an ideal seal material choice in a number of applications. FKM material are widely used in chemical, modern aerospace, missiles, rockets, space navigation, ships, atomic energy and other leading-edge technology and automotive, shipbuilding, chemistry, petroleum, telecommunications, equipment, machinery and other industrial applications.
Chemical Industry (Performed well in strong acid corrosion, strong alkali corrosion, gas corrosion, organic solvent corrosion, high temperature corrosion environment.)
Machinery Industry (Performed well in high stretch strength and hardness).
Engine industry, chemical industry, deep well oil industry, steam-related industry.
HUAYI has many kinds of other specialty FKM compounds available. Contact a HUAYI Sales Consultant or Engineer for more information.