FKM Rubber vs Silicone Rubber - Find Out Their Characteristics!

Synthetic elastic materials are widely used in our daily life and frequently applied in various fields, such as thermal insulation products, electronic devices, medical equipment, chemical industry, even aerospace components and petroleum refining equipment, etc. However, did you know that actually there are suitable elastic materials to be used in each field? This article will introduce two types of elastic materials with distinct characteristics: "FKM rubber" and "silicone rubber." Let's explore how they are practically used in our everyday life.

Characteristics of FKM rubber

Fluoroelastomer (FKM) is a special synthetic rubber material, also known as fluoro rubber. It is an elastic material with excellent corrosion resistance and high temperature stability. The following are the main characteristics of FKM rubber：

Corrosion Resistance

FKM rubber demonstrates excellent corrosion resistance to a wide range of chemical substances, including acids, alkalis, organic solvents, and oils, etc. This makes FKM rubber an ideal material for use in corrosive environments, such as the chemical and petroleum industries. FKM rubber exhibits superior corrosion resistance compared to other types of rubber, withstanding various organic solvents, inorganic acids, strong oxidizing agents, and oils.

High Temperature Stability

FKM rubber can maintain their elasticity and physical properties even at extremely high temperatures. They can withstand temperatures of up to approximately 250°C while retaining their mechanical strength and dimensional stability. The high temperature stability of FKM rubber makes them an ideal choice for many high-temperature applications, such as automotive engine seals, aerospace components, and petrochemical equipment.

Low Coefficient of Friction

FKM rubber has an extremely low coefficient of friction, making them highly useful in many sealing and rolling applications. The coefficient of friction is an indicator of the sliding friction resistance between two surfaces. Due to their unique chemical structure and surface properties, FKM rubber exhibits an exceptionally low coefficient of friction. As a result, they can reduce energy loss and wear in various mechanical contact and motion applications, thus extending the material's service life.

Good Electrical Insulation

FKM rubber possesses excellent electrical insulation, allowing them to provide reliable insulation protection in high-voltage and high-frequency applications. They can effectively prevent the flow of electric current and block the leakage and discharge of electric charges. FKM rubber maintain dependable insulation protection in high-pressure environments. As a result, it finds wide application in power systems, electronic products, and high-voltage equipment. FKM rubber has become one of the preferred materials in many electrical and electronic fields.

Excellent Sealing Function

FKM rubber exhibits excellent sealing function, effectively blocking the penetration of gases and liquids. Therefore, they are widely used in sealing applications such as automotive engine gaskets and industrial pipeline joints. Due to their outstanding gas tightness, FKM rubber surpasses other elastomeric materials in terms of weather resistance, flame resistance, radiation resistance, and vacuum resistance. Hence, FKM rubber is the preferred choice for many specialized applications in fields such as aerospace, energy, chemical, and nuclear industries.

High Fluorine Content

FKM rubber generally refers to fluoroelastomers with a fluorine content of 66% in the base polymer. The chemical resistance of FKM rubber is related to their fluorine level. In general, higher fluorine content leads to stronger resistance against chemical corrosion. Below, we will explain the differences and respective application areas between two types of FKM rubber with different fluorine content.

一、High Fluorine Rubber

High fluorine rubber is a variant of FKM rubber, also known as fluorinated rubber or fluoroether rubber. It has a fluorine content ranging from 67% to 70%. It is suitable for general applications or object with relatively lower chemical resistance requirements. Using FKM materials with lower fluorine content yet still exhibiting good performance may be a more economical and practical choice. High fluorine rubber is a material formed by copolymerization of fluorine-containing monomers with rubber substrates. Compared to traditional FKM rubber, high fluorine rubber has the following characteristics：

• Extremely High Corrosion Resistance：High fluorine rubber possesses excellent corrosion resistance, capable of withstanding the attack of various highly corrosive media, including strong acids, strong alkalis, organic solvents, oxidizing agents, etc. It is widely used in industries such as chemical and petrochemical sectors.

• Excellent High-Temperature Stability：High fluorine rubber is able to maintain its stability and physical properties at extremely high temperatures. It can withstand temperatures of up to approximately 300°C while retaining its mechanical strength and dimensional stability.

• Extremely Low Surface Tension：High fluorine rubber exhibits extremely low surface tension, particularly outstanding in terms of resistance to contamination, anti-adhesion, and ease of cleaning. It finds wide applications in various fields such as food processing, medical devices, semiconductor manufacturing, etc.

• Excellent Electrical Insulation Performance：High fluorine rubber possesses outstanding electrical insulation properties, effectively preventing the passage of electric current and providing reliable insulation protection in high-voltage and high-frequency applications.

In conclusion, high fluorine rubber is a special rubber material that possesses excellent corrosion resistance, high-temperature stability, low surface tension, and excellent electrical insulation. It finds wide applications in various extreme environments and specialized industries, including chemical industry, petrochemical industry, food processing, medical devices, semiconductor manufacturing, etc.

二、Perfluoroelastomer

Perfluoroelastomer, also known as perfluoropolymer or perfluorinated rubber, is a special type of FKM rubber. It is a material formed by copolymerization of perfluorinated carbon-fluorine compounds with rubber substrates. As a result, the base rubber has a fluorine content of over 70%. FKM rubber with higher fluorine content exhibits stronger chemical resistance, but it also comes with a higher price. Perfluoroelastomer is suitable for applications that require higher environmental performance. Here are some characteristics of perfluoroelastomer：

• Extremely High Corrosion Resistance：Perfluoroelastomer exhibits exceptional corrosion resistance, capable of resisting the attack of strong acids, strong alkalis, organic solvents, oxidizing agents, and other corrosive media. They are frequently employed in industries such as chemical, petrochemical, and electronic manufacturing.

• Excellent High-Temperature Stability：Perfluoroelastomer can maintain stability and physical properties at extremely high temperatures. They can withstand temperatures of up to approximately 300°C while retaining their mechanical strength and dimensional stability.

• Excellent Electrical Insulation Performance：Perfluoroelastomer exhibits outstanding electrical insulation properties, effectively blocking the passage of electric current and providing reliable insulation protection in high-voltage and high-frequency applications. This makes perfluoroelastomer widely used in the electronics and power industries.

• Low Surface Energy：Perfluoroelastomer has an extremely low surface energy, which gives them excellent non-stick properties and ease of cleaning. This makes them widely adopted in applications such as food processing, pharmaceuticals, semiconductor manufacturing, etc.

In summary, perfluoroelastomer is a special rubber material that possesses outstanding corrosion resistance, high-temperature stability, excellent electrical insulation performance, and low surface energy. It finds widespread applications in various fields, including chemical industry, petrochemical industry, electronics manufacturing, food processing, medical devices, etc.

Characteristics of Silicone Rubber

Silicone rubber, also known as siloxane rubber, is a synthetic elastomeric material formed by organic silicon polymers. Its main component is silicone rubber, which is a soft, flexible, and high-temperature resistant synthetic material. Silicone is considered a 100% green and environmentally friendly material. Here are some characteristics of silicone rubber：

High Temperature Resistance

Silicone rubber is an excellent high-temperature material that can maintain its physical properties and elasticity at extremely high temperatures. It can typically withstand temperatures of over 300°C and exhibits exceptional performance stability in high-temperature environments. As a result, silicone rubber is commonly used in everyday life for heat-insulating products such as silicone baking molds, silicone oven gloves, insulation pads, insulated beverage sleeves, and various other silicone applications.

Elasticity and Flexibility

Silicone rubber exhibits excellent elasticity and stretching ability, allowing it to return to its original shape after deformation. This characteristic makes silicone widely used in many sealing and cushioning applications, particularly in applications that require high elasticity. Common examples include seals, elastic films, and elastic components.

Excellent Weather Resistance

Silicone rubber possesses outstanding weather resistance, enabling it to withstand the effects of ultraviolet (UV) radiation, oxygen, moisture, and certain chemicals. This makes silicone advantageous for outdoor applications and prolonged exposure to harsh environments.

Good Electrical Insulation Performance

Silicone possesses excellent insulation performance, effectively insulating electric current. This makes silicone commonly used in the insulation and encapsulation of electronic components. It finds wide applications in insulating and protecting electronic components such as wire insulation and electronic packaging.

Good Biocompatibility

Silicone rubber is a material with excellent biocompatibility, meaning it is unlikely to cause allergies or other adverse reactions when in contact with the skin or body tissues. Due to this property, silicone is commonly used in medical devices, healthcare products, and food-grade contact materials.

The Differences between FKM Rubber and Silicone Rubber

In general, FKM rubber and silicone rubber have their own unique characteristics, which make them suitable for different application areas. FKM rubber excels in terms of corrosion resistance and high-temperature stability, making it suitable for corrosive environments and high-temperature applications. On the other hand, silicone rubber exhibits high-temperature resistance, flexibility, and weather resistance, making it suitable for high-temperature environments, sealing, and applications with high weathering requirements. When selecting a material, it is important to choose the appropriate one based on the specific application requirements.

FKM Rubber vs Silicone Rubber

Conclusion

Whether you need FKM rubber with excellent chemical resistance and high-temperature performance or silicone rubber with insulation and elasticity, Glory Sun Group can provide professional OEM services! We have been specializing in the manufacturing of silicone rubber products for over 30 years. From mold making to shipping, the entire process is completed in-house. We employ state-of-the-art equipments, rigorous production management, quality verification, and inspection to ensure the highest quality, so you can 100% trust us. Click here to contact us for further inquiries .