FKM vs. VMQ

Attribute	FKM	VMQ
Chemical Structure	Fluorocarbon	Silicone
Temperature Range	-20°C to 200°C	-60°C to 230°C
Resistance to Ozone	Good	Good
Resistance to Oil	Good	Poor
Resistance to Water	Good	Good

Introduction

When it comes to choosing the right material for sealing applications, two popular options are FKM (fluoroelastomer) and VMQ (silicone). Both materials have unique attributes that make them suitable for different environments and conditions. In this article, we will compare the key characteristics of FKM and VMQ to help you make an informed decision for your specific sealing needs.

Chemical Resistance

FKM is known for its excellent resistance to a wide range of chemicals, including oils, fuels, and solvents. This makes it a preferred choice for applications where exposure to harsh chemicals is a concern. On the other hand, VMQ has good resistance to water, ozone, and extreme temperatures, but it may not be as effective as FKM when it comes to withstanding aggressive chemicals.

Temperature Range

One of the key differences between FKM and VMQ is their temperature resistance. FKM can withstand high temperatures up to 200°C, making it ideal for applications where heat resistance is crucial. VMQ, on the other hand, has a lower temperature range and is typically used in applications that do not require high heat resistance. It is important to consider the operating temperature of your application when choosing between FKM and VMQ.

Compression Set

FKM has a lower compression set compared to VMQ, which means it can maintain its shape and sealing properties over a longer period of time. This makes FKM a reliable choice for applications where compression set is a concern, such as in automotive or aerospace industries. VMQ, on the other hand, may experience higher compression set over time, leading to potential leakage or failure in sealing applications.

Flexibility and Elasticity

VMQ is known for its flexibility and elasticity, which allows it to conform to irregular shapes and surfaces. This makes VMQ a versatile choice for applications where flexibility is important, such as in medical devices or food processing equipment. FKM, on the other hand, may be less flexible than VMQ, but it offers superior resistance to abrasion and tearing, making it suitable for demanding sealing applications.

Cost Considerations

When it comes to cost, FKM is generally more expensive than VMQ due to its superior chemical resistance and temperature range. While FKM may have a higher upfront cost, it can provide long-term cost savings by reducing the need for frequent replacements or repairs. VMQ, on the other hand, is a more cost-effective option for applications that do not require the same level of performance as FKM.

Conclusion

In conclusion, both FKM and VMQ have unique attributes that make them suitable for different sealing applications. FKM offers excellent chemical resistance and high temperature range, making it ideal for demanding environments. VMQ, on the other hand, provides good flexibility and elasticity at a lower cost. Ultimately, the choice between FKM and VMQ will depend on the specific requirements of your application and the level of performance needed. By considering the key characteristics of each material, you can make an informed decision that meets your sealing needs effectively.