What is FKM rubber?

FKM is a type of synthetic rubber known for its exceptional resistance to heat, chemicals, and oils. It was developed to address the need for a high-performance polymer with high resistance levels. At TRP Polymer, we manufacture FKM rubber for a number of different applications and industries. Continue reading to find out more.

What is FKM rubber?

FKM stands for fluoroelastomer and is a type of synthetic rubber known for its excellent resistance to chemicals, oils and heat. It’s a high-performance elastomer that’s often used in applications where traditional rubber materials cannot withstand extreme conditions. Fluoroelastomer was born out of necessity during the Second World War. It was devised as the solution to leaking nitrile seals that were used on aircrafts during that time period.

Fluorinated polymers were developed and contained chemically inert Fluorine-Carbon bonds that delivered a high level of resistance to chemicals. By the latter stages of the 1950s, FKM types 1 and 2 were commercially available and offered increased chemical resistance.

The fluorine content increased dramatically from around 26.7% to 66% – 68%. In more recent times, polymer design has continued to improve due to a greater understanding of the polymer architecture

What are the properties of FKM rubber?

The key properties of fluoroelastomers include:

  • High-temperature resistance: FKM rubber can withstand temperatures ranging from -20°C to 200°C (-4°F to 392°F). For short time periods a higher temperature of service may be applied
  • Good resistance to chemicals – FKM rubber is resistant to a variety of chemicals, including acids, fuels, and industrial solvents.
  • Weather and UV resistance – Fluoroelastomers are also known for excellent resistance to weathering, ozone, and UV radiation, which makes them suitable for outdoor applications.
  • High mechanical strength – FKM rubber offers good mechanical properties, including flexibility and resilience.
  • Low gas permeability – Low gas permeability is a key property of FKM rubber. This makes it suitable for applications where sealing against fluids critical.
  • Excellent compression set – FKM rubber maintains its shape and sealing properties even after prolonged compression.

What are the advantages of FKM rubber?

There are a number of different benefits that FKM rubber offers. These advantages include:

  • Wide temperature range (-45°C – 200°C)
  • Excellent resistance to chemicals, gas and liquid permeation resistance
  • Excellent resistance to weather and ozone
  • High-density and high-quality feel
  • Good mechanical properties
  • Improved sealing performance with a good compression set
  • Suitable for explosive decompression, CIP, SIP, FDA and EC1934/2004
  • Lower long term cost when compared to single use seals

What are the disadvantages of FKM rubber?

While there are many advantages of FKM rubber, there are some disadvantages to consider. These include:

  • It can swell in fluorinated solvents
  • Higher initial cost than non-fluorinated hydrocarbons
  • Shouldn’t be used with molten or gaseous alkali metals
  • Not as chemically resistant as FFKM and has a smaller temperature range
  • Choosing the wrong FKM for an application can lead to rapid failure
  • Low-temperature grades can be costly

Which applications use FKM rubber?

Due to its high resistance to chemicals, oils and heat, FKM rubber is widely used across a number of industries and applications. They include:

  • Aerospace – FKM rubber is used in aircraft and spacecraft for seals, gaskets, and O-rings because of its ability to withstand high temperatures and extreme conditions. TRP stocks material meeting various aerospace standards such as DTD 5612a, MIL specs and SAE specs.
  • Automotive – Seals, gaskets and O-rings are also used in the automotive industry due to its excellent oil and fuel resistance. TRP services high end and consumer automotive customers. Recently TRP have been involved in electrical vehicles, supplying insulative seals, conductive seals such as conductive silicone and EMI/RFI shielding silicones. 
  • Chemical processing – In chemical manufacturing and processing industries, fluoroelastomers are used for seals and gaskets that come into regular contact with corrosive chemicals.
  • Oil and gas – Oil and gas applications use FKM rubber for seals and gaskets in pipelines, valves, drilling equipment, pipelines, and other components that are regularly exposed to aggressive fluids and high temperatures. TRP offers RGD resistant seals approved to NORSOK and ISO23936_2.
  • Pharmaceutical and food processing – Due to its high chemical resistance and the ability to meet stringent hygiene standards, FKM rubber is used in equipment and machinery in pharmaceutical and food processing applications. TRP offer grades approved to 21CFR177.2600 (e,f) and USP class 6.
  • Military and defence – FKM rubber is also used in a wide variety of military and defence applications, including vehicles and aircraft where durability and reliability are absolutely essential.

FKM rubber at TRP Polymer

At TRP Polymer, we pride ourselves on being a leader in the field of rubber manufacturing. We produce high-quality FKM rubber for a wide range of industries and applications. From custom rubber seals to custom moulded rubber solutions, you can find an excellent selection of fluoroelastomers at TRP Polymer.

You can read more about our other polymer materials, such as FFKMs here. For any more information or questions you may have, don’t hesitate to contact us.