Fluoropolymers like FKM rubber or Viton™ are highly desired for a wide range of applications, especially those that require excellent high-temperature and chemical resistance. However, the implications of potential PFAS regulations have caused many companies to begin evaluating alternatives to protect and diversify their product lines.
While not an exact equivalent, HNBR (hydrogenated nitrile butadiene rubber) may serve as a potential alternative to FKM in certain applications due to its similar performance characteristics.
FKM & HNBR Similarities
- Strong chemical & oil resistance
- Generally characterized as a premier performance material
- Longer shelf life compared to other organic polymers
- Excellent weathering and ozone resistance
- Generally resists higher temperatures than other organic rubber materials
FKM Rubber Advantages to HNBR
- FKM resists a wider range of chemicals
- FKM has stronger electrical properties and flame resistance
- FKM generally has a longer service life in extreme high temperature applications
- FKM provides superior resistance to corrosive chemicals, such as solvents and acids
HNBR Rubber Advantages to FKM
- Although formulation compositions may vary between manufacturers, HNBR compounds are generally PFAS-free which can help avoid additional regulatory considerations
- HNBR tends to produce fewer byproducts under extreme heat
- HNBR exhibits less volume loss in abrasive applications
- Robust mechanical performance in dynamic applications
- HNBR is generally more cost effective
- HNBR performs better in lower-temperature settings
Material Applications
FKM (Viton™) and HNBR rubber gaskets, o-rings and seals are regularly deployed in aerospace, military and defense, automotive, chemical processing, and oil & gas applications. Considering industry trends, FKM (Viton™) is more commonly used in aerospace applications, whereas HNBR is more frequently found in oil & gas applications, especially where low-temperature resistance is essential.
WARCO FKM (Fluorozone®, Viton™) and HNBR
Although HNBR and FKM share many similarities, selecting the right material ultimately comes down to the demands of your specific application. During your evaluation, it is best to consult with the end user to assess specific requirements and utilize a compounding expert to determine whether HNBR or FKM / Viton™ will meet those requirements.
WARCO regularly manufactures HNBR and FKM / Viton™ as sheet rubber, rubber extrusions, rubber seals, rubber gaskets, and custom-molded rubber parts. We invite you to leverage our team’s experience and elastomeric expertise when you receive requests for these materials.
If you have any questions, email your questions to sales@warco.com, or contact us directly at (714) 532-3355.
