FPM vs. Viton

Attribute	FPM	Viton
Chemical Resistance	Excellent	Excellent
Temperature Range	-20°C to 200°C	-15°C to 204°C
Compression Set	Good	Good
Cost	Higher	Lower

Introduction

Fluoroelastomers are widely used in various industries due to their excellent resistance to heat, chemicals, and oils. Two popular types of fluoroelastomers are FPM (fluorocarbon rubber) and Viton. While both materials offer similar benefits, there are key differences that make each suitable for specific applications.

Chemical Composition

FPM is a copolymer of hexafluoropropylene (HFP) and vinylidene fluoride (VDF). It contains a high percentage of fluorine, which gives it superior resistance to chemicals and oils. On the other hand, Viton is a brand of fluoroelastomer made by DuPont, which is a terpolymer of vinylidene fluoride (VDF), hexafluoropropylene (HFP), and tetrafluoroethylene (TFE). This unique composition provides Viton with enhanced mechanical properties compared to FPM.

Temperature Resistance

One of the key differences between FPM and Viton is their temperature resistance. FPM has a maximum continuous operating temperature of around 200°C, making it suitable for high-temperature applications. In contrast, Viton can withstand temperatures up to 250°C, making it ideal for even more demanding environments where extreme heat is a factor.

Chemical Resistance

Both FPM and Viton exhibit excellent resistance to a wide range of chemicals, including acids, bases, fuels, and solvents. However, Viton has a slight edge over FPM when it comes to resistance to aggressive chemicals such as concentrated acids and ketones. This makes Viton the preferred choice for applications where exposure to harsh chemicals is a concern.

Compression Set

Compression set refers to the ability of a material to retain its shape after being compressed. FPM has a lower compression set compared to Viton, which means it can maintain its original form better under pressure. This makes FPM a better choice for sealing applications where compression set is a critical factor.

Flexibility and Elasticity

When it comes to flexibility and elasticity, Viton outperforms FPM due to its unique terpolymer composition. Viton can stretch and bend without losing its shape or mechanical properties, making it ideal for applications that require a high degree of flexibility, such as O-rings and seals in dynamic systems.

Cost

Cost is another important factor to consider when choosing between FPM and Viton. FPM is generally more affordable than Viton, making it a cost-effective option for applications where high performance is not a primary concern. However, the superior properties of Viton may justify the higher cost in applications where performance and durability are critical.

Conclusion

In conclusion, both FPM and Viton are excellent choices for applications that require high heat and chemical resistance. While FPM offers better compression set and cost-effectiveness, Viton provides superior temperature resistance, chemical resistance, flexibility, and elasticity. The choice between FPM and Viton ultimately depends on the specific requirements of the application and the importance of each attribute in the given context.