FPM, FKM, and Viton are terms often used interchangeably in the rubber industry. But are they really the same? Let’s break down the key differences and similarities between them.
FPM, FKM, and Viton are all types of fluoroelastomers. They share similar properties but have distinct manufacturing processes and applications.
In this article, we will dive deep into the characteristics of FPM, FKM, and Viton, as well as how they compare in performance and cost.
Are Viton and FKM the same?
When discussing FKM and Viton, many assume they are identical. However, there are subtle but important distinctions.
Viton is a brand name for a specific type of FKM, a fluoroelastomer. While they share many similarities, the key difference lies in the brand’s manufacturing standards and formulations.
What makes Viton different from other FKM?
Viton is a proprietary version of FKM, a synthetic rubber made primarily of fluorine, carbon, and hydrogen atoms. It is produced by the chemical company DuPont under the name "Viton1," which is why it has become synonymous with FKM in many industries. While FKM refers to the broader category of fluoroelastomers, Viton is specifically known for its superior chemical resistance, high-temperature tolerance, and durability.
FKM and Viton chemical properties
| Property | FKM (General) | Viton (Specific Brand) |
|---|---|---|
| Temperature resistance | High (up to 250°C) | Very high (up to 300°C) |
| Chemical resistance | Excellent | Superior in aggressive chemicals |
| Cost | Moderate | Higher due to brand exclusivity |
What is the common name for FKM?
FPM, FKM, and Viton can be confusing due to their overlapping terminology. So, what is the common name for FKM?
The common name for FKM is fluoroelastomer, which refers to a family of synthetic rubber materials made with fluorine-based polymers.
Fluoroelastomers Explained
Fluoroelastomers2 are known for their resistance to high temperatures, chemicals, and oils. FKM is just one type of fluoroelastomer, with Viton being the most widely recognized. They are commonly used in demanding applications like seals, gaskets, and o-rings, where exposure to harsh environments is a concern.
FKM Applications
Some common applications for FKM include:
- Automotive: Fuel systems, seals, and gaskets
- Aerospace: O-rings for fuel systems
- Chemical industry: Seals for aggressive chemicals
What are the disadvantages of FKM?
While FKM has many advantages, it also has some drawbacks that you should consider before using it in your products.
Despite its high chemical resistance, FKM can be prone to aging and degradation under extreme conditions, and it is more expensive than other rubber options.
Drawbacks of FKM
- Cost: FKM is one of the most expensive types of rubber, making it less suitable for cost-sensitive applications.
- Hardness: It tends to be more rigid than other rubbers, which may affect its flexibility.
- Limited tear strength: FKM has lower tear resistance compared to other elastomers like EPDM3 or NBR4.
Common alternatives to FKM
| Material | Cost | Temperature Resistance | Chemical Resistance |
|---|---|---|---|
| FKM (Viton) | Expensive | High (up to 300°C) | Excellent |
| EPDM | Moderate | High (up to 150°C) | Good |
| NBR | Low | Moderate (up to 120°C) | Moderate |
What hardness is FKM Viton?
The hardness of FKM Viton is an important consideration in determining its suitability for various applications. Let’s take a closer look.
Viton typically has a hardness range of 50-90 Shore A, which is ideal for sealing applications where flexibility and durability are needed.
Hardness Range of FKM
The hardness of Viton can be adjusted depending on the formulation and the specific application. However, most Viton compounds fall between 60 to 90 Shore A. This hardness level offers a balance between flexibility and strength, which is crucial for seals and gaskets.
Why hardness matters in FKM
The right hardness is important for the performance of seals and gaskets, as it affects their ability to create a reliable seal under pressure. A softer compound may offer better flexibility, while a harder compound can provide greater resistance to deformation.
Why is FKM so expensive?
If you’re wondering why FKM is one of the most expensive rubber materials available, there are several factors at play.
The cost of FKM5 is driven by its complex manufacturing process, the quality of raw materials, and the high-performance characteristics it offers.
Factors Contributing to the High Cost of FKM
- Raw Materials: FKM is made from high-grade, fluorinated polymers that are more costly than other elastomers.
- Manufacturing Process: The process for producing FKM requires precision and advanced technology, which contributes to its higher price.
- Performance: The superior resistance to chemicals, oils, and high temperatures makes FKM ideal for demanding applications, adding to its value.
Comparing FKM's Cost to Other Rubber Types
| Rubber Type | Cost | Temperature Resistance | Chemical Resistance | Durability |
|---|---|---|---|---|
| FKM (Viton) | High | Very High (up to 300°C) | Excellent | Very High |
| EPDM | Low | Moderate (up to 150°C) | Good | Moderate |
| NBR | Low | Moderate (up to 120°C) | Moderate | Moderate |
Conclusion
FPM, FKM, and Viton may seem similar, but they have distinct characteristics that make them suitable for specific applications. Viton, as a brand of FKM, stands out due to its superior performance, though it comes at a higher cost. FKM offers excellent resistance to chemicals and high temperatures but is less flexible and more expensive than alternatives.
Footnotes：
Viton is a well-known brand of FKM, developed by DuPont. It offers superior chemical resistance and high temperature tolerance, making it a popular choice in demanding industrial applications. ↩
Fluoroelastomers like FKM are known for their excellent chemical and temperature resistance, making them ideal for use in automotive, aerospace, and chemical industries. ↩
EPDM (Ethylene Propylene Diene Monomer) is another type of elastomer known for its excellent resistance to heat, ozone, and weathering. ↩
NBR (Nitrile Butadiene Rubber) is a synthetic rubber that is especially resistant to oils, fuels, and other chemicals, making it commonly used in seals and gaskets. ↩
Explore the factors that contribute to the high cost of FKM, including raw materials and manufacturing processes. ↩
