A Complete Guide to Viton Rubber

Viton rubber, a high-performance fluoroelastomer, demonstrates exceptional performance when exposed to challenging environments, including extreme temperatures and harsh weather conditions. As a synthetic rubber recognised for its excellent chemical resistance, it is invaluable across multiple industry sectors. Its robust sealing properties make it suitable for aerospace, automotive and chemical processing applications. Withstanding high temperatures and exhibiting low gas permeability, Viton remains the material of choice for sealing components in critical equipment and systems that require a material known for its reliability and longevity.

Viton is available in a commercial grade, known as Viton FKM, and genuine Viton™, a brand name for fluorocarbon rubber polymers of The Chemours Company. These materials offer different performances, resistance to chemicals and flexibility at low temperatures. They can be supplied as Viton sheet or extruded profiles.

This article provides a detailed background to the history of Viton and how it can be used for manufacturing bespoke sealing solutions. It also details the benefits of using this material for sealing applications.

Viton rubber boasts many advantages for manufacturing custom extrusions. As a compound with exceptional chemical resistance and resilience in harsh environments, it is often the material of choice for industries that require reliability. Some of the advantages that make Viton dependable for sealing applications include;

• Chemical Resistance: One of the most sought after benefits of Viton is its resistance to chemicals, oils, fuels and solvents. As a material that remains stable when in contact with corrosive elements, Viton provides a reliable choice for applications where other materials may fail. Viton is also hydrophobic, which means that it repels water and resists the penetration of oil and water-based liquids.
  
  
• Temperature Range: Operating within a temperature range of -15°C to 205°C, Viton rubber is known for its excellent temperature resistance. It maintains its mechanical properties at elevated temperatures, making it suitable for applications where it will be exposed to high heat. As well as withstanding temperatures up to 205°C, Viton seals can also withstand short intermittent exposure of approximately 300°C. Viton also remains flexible below freezing without cracking, splitting or any other degradation of its physical properties. These characteristics make it suitable for exceptionally low and high-temperature environments, such as aerospace and industrial settings, where exposure to extreme temperatures is likely.
  
  
• Weathering: As Viton can withstand exposure to the elements, it is suitable for use in outdoor environments. It is relatively inert to ultraviolet (UV) so will not degrade or discolour when installed in areas subjected to prolonged sunlight exposure. Viton also demonstrates outstanding water resistance and is impermeable to moisture.

As well as exhibiting excellent resistance to most substances, fluids and environmental elements, Viton offers further characteristics that position it as a versatile and high-performance material. These characteristics include;

• Low Gas Permeability: Although the permeability of gases is influenced by factors such as temperature and pressure, Viton has low gas permeability. This is beneficial in sealing applications as it limits the passing of corrosive or reactive gases that may degrade the material or compromise its structural integrity. Gas impermeability also provides a level of insulation helping maintain temperature and pressure within a specific area.
  
  
• Durability: Viton has a unique set of robust mechanical properties that ensures consistent performance and provides durability in most sealing applications. Together with this ability to withstand most fluids, Viton is suitable for tough and dirty environments without the risk of degrading or deteriorating.
  
  
• Elasticity and Flexibility: Unlike some other synthetic compounds, Viton demonstrates good tensile strength. This makes it flexible, resilient and able to maintain its shape and function under stress.
  
  
• Low Compression Set: Products manufactured from Viton exhibit a good resistance to compression set by retaining their original shape and sealing properties after compression. Unlike other materials that are damaged with prolonged compression, Viton ensures reliable performance.
  
  
• Resistance to Aging: Viton demonstrates resistance to aging and degradation which contributes to long-term reliability. Prolonged exposure to most fluids will not cause the rubber to degrade.

While Viton rubber offers many advantages in tough and hostile environments, there are a number of potential disadvantages that may make it unsuitable for certain applications. In some cases, the disadvantages may be outweighed by the materials unique combination of properties, whilst in others, an alternative elastomer may be more appropriate. Some of these disadvantages include;

• Cost: As a high-performance material, Viton is significantly more expensive than other synthetic rubber compounds due to the manufacturing process and raw material cost. However, the higher cost can often be justified when considering that its resistance to aging and longevity allows you to purchase a product that needs to be replaced less frequently than sealing solutions manufactured from other materials.
  
  
• Hardness: Depending on the specific formulation, Viton rubber can be relatively hard compared to other materials. For applications that require a softer or more flexible material you may choose to consider alternative materials, such as EPDM or Silicone, which can be extruded in a selection of hardnesses.
  
  
• Limited Resistance to Certain Chemicals: Although Viton provides excellent resistance to most substances, it may experience a small degree of swelling if exposed to certain chemicals. These include Skydrol, amines, esters and hot hydrofluoric acids. It is essential to carefully evaluate any contact substances to determine if Viton is the most suitable material.

Whilst Viton is generally resistant to weathering, extreme temperatures and harsh chemicals, the specific performance may vary depending on the exact type of material used. Viton is available in two variants; genuine Viton™ and Viton FKM, which is a lower cost copy with similar characteristics. These variants can be manufactured in different grades containing different amounts of fluorine which has an impact on its resistance to chemicals. As the percentage of fluorine increases, its flexibility at low temperatures decreases.