FKM vs. FPM

Attribute	FKM	FPM
Material Type	Fluoroelastomer	Fluoropolymer
Temperature Resistance	Excellent	Excellent
Chemical Resistance	Excellent	Excellent
Compression Set Resistance	Good	Excellent
Cost	Higher	Lower

Introduction

Fluoroelastomers (FKM) and Fluorocarbon Rubber (FPM) are both high-performance elastomers known for their excellent resistance to heat, chemicals, and oils. While they share some similarities, there are also key differences between the two materials that make them suitable for different applications. In this article, we will compare the attributes of FKM and FPM to help you understand their unique characteristics.

Chemical Composition

FKM is a copolymer of hexafluoropropylene (HFP) and vinylidene fluoride (VDF), while FPM is a copolymer of tetrafluoroethylene (TFE) and propylene. The difference in chemical composition results in variations in their physical properties and performance characteristics. FKM is known for its superior resistance to a wide range of chemicals, including acids, bases, and solvents. On the other hand, FPM offers better resistance to oils and fuels, making it a preferred choice for applications in the automotive and aerospace industries.

Temperature Resistance

Both FKM and FPM exhibit excellent heat resistance, with the ability to withstand high temperatures without losing their mechanical properties. FKM has a higher operating temperature range compared to FPM, making it suitable for applications where extreme heat is a concern. FPM, on the other hand, has a lower temperature resistance but offers better flexibility at low temperatures. This makes FPM a preferred choice for applications that require a balance between high and low-temperature performance.

Compression Set

Compression set refers to the ability of an elastomer to recover its original shape after being compressed. FKM has a lower compression set compared to FPM, which means it maintains its sealing properties over a longer period of time. This makes FKM ideal for applications where a tight seal is critical, such as in the oil and gas industry. FPM, on the other hand, may experience higher levels of compression set over time, leading to potential leaks or failures in sealing applications.

Physical Properties

FKM and FPM have different physical properties that make them suitable for specific applications. FKM is known for its excellent resistance to abrasion, tearing, and punctures, making it a durable choice for demanding environments. FPM, on the other hand, offers better flexibility and elasticity, making it easier to install and remove in tight spaces. The choice between FKM and FPM will depend on the specific requirements of the application, such as resistance to wear and tear or ease of installation.

Cost Considerations

When comparing FKM and FPM, cost is an important factor to consider. FKM is generally more expensive than FPM due to its superior chemical resistance and high-temperature performance. While FKM may have a higher upfront cost, its longer lifespan and reduced maintenance requirements can result in cost savings over time. FPM, on the other hand, is a more cost-effective option for applications where extreme chemical resistance or temperature resistance is not required.

Applications

FKM and FPM are used in a wide range of industries and applications due to their unique properties. FKM is commonly used in the automotive, aerospace, and oil and gas industries for sealing and gasket applications. Its excellent chemical resistance and high-temperature performance make it ideal for demanding environments. FPM, on the other hand, is preferred in applications where resistance to oils, fuels, and lubricants is critical, such as in the automotive and marine industries.

Conclusion

In conclusion, FKM and FPM are both high-performance elastomers with unique attributes that make them suitable for different applications. While FKM offers superior chemical resistance and high-temperature performance, FPM excels in applications requiring resistance to oils and fuels. The choice between FKM and FPM will depend on the specific requirements of the application, such as temperature range, chemical exposure, and cost considerations. By understanding the differences between FKM and FPM, you can make an informed decision when selecting the right elastomer for your application.