Being in the nonmetallic manufacturing industry requires us to become familiar with a long list of materials, each with their own qualities, strengths, and weaknesses. One of these materials is fluorocarbon rubber (FKM); commonly referred to by its DuPont-christened name Viton. What is Viton and what qualities does it boast? Let’s take a look:
As mentioned, Viton is DuPont’s (now Chemours) brand name for fluorocarbon rubber. This is a synthetic rubber and fluoropolymer elastomer and is commonly used for O-rings and other molded or extruded parts.
So, what is Viton good for? Viton’s properties make it an ideal choice for an environment where certain challenges and factors are present. These include:
High temperatures: Viton O-rings withstand temperatures from -20°C to 210°C (-4°F to 410°F).
Chemicals: Viton can withstand a wide range of chemicals: these include oils, acids, silicone fluids, and gases, as well as halogenated and aromatic hydrocarbons.
Environmental challenges: Viton can maintain a seal even when oxidation, UV exposure, weather, ozone, fungus, and mold would’ve ruined other seals.
Taken together, these qualities make Viton a common choice for appliance processing, automotive, and chemical industries.
Currently, Chemours offers more than 25 different FKM polymers, with differing fluorine content, viscosity, and curing methods. Generally speaking, a higher fluorine content brings higher chemical resistance; polymers with lower viscosity are great for extrusions and to help mold complex parts; and a variety of curing mechanisms highlight specific properties.
Viton is a black rubber material ideal for O-Rings in high-temperature situations.
What about the disadvantages of Viton? Well, the first point to recognize would be its low-temperature performance—or lack thereof. See, while FKM’s performance in high-temperature situations is exceptional, it loses this high level of performance in colder situations. Other low-temperature polymers can work in -40°C (-40°F) conditions while 3M has another specialty polymer which, depending on its application, can withstand -60°C (-76°F).
Another note about Viton is that it tends to be a much more expensive material than other nitrile components. The reason for this comes down to the properties of Viton (especially the temperature range as well as its chemical and environmental resistances) which means it will last longer than nitrile in tougher conditions. However, there will be jobs in which those properties are unnecessary—in these cases, is the extra expense really worth it?
Therefore, like any other manufacturing materials, there is no one-size-fits-all solution, which is why it’s crucial to thoroughly consider the part’s applications and working conditions and research many available materials before arriving at the final decision for what the part will be made of. However, as noted in the introduction of this blog, there are so many materials available, and that list can be overwhelming. Even if you’ve decided to go with a Viton part, well, now you have to choose between Chemours’ 25 different variants on the basic Viton. All this together makes the value of having a team of specialists in nonmetal manufacturing will save you the time and money you would doubtlessly find yourself investing in the research and development phases of part manufacturing. So, if you need help navigating the tumultuous seas of nonmetal seals and gaskets, the Breiner team is ready.
Viton® is a specific brand of Fluorocarbon (FKM) and is a registered trademark of The Chemours Company. This synthetic rubber polymer is commonly used in o-ring applications for aircraft engines, automotive fuel handling systems and other applications requiring high temperatures and low compression set.
One of the first steps in designing a rubber seal is choosing the right material for your application. This is a critical stage in development, as every rubber compound carries its own strengths, weaknesses and sealing capabilities. Before choosing Viton® as your trusted material, here’s everything you need to know about it.
Viton® has outstanding resistance to heat. In fact, one Viton® o-ring can withstand temperature ranges from -13°F to 446°F. Since some rubber compounds are known to fail in extreme high-temperature environments, Viton® is a great candidate for applications working under these circumstances.
Viton® also is known for its excellent chemical resistance, making it a universal o-ring material. When rubber is introduced to chemicals, it can absorb the fluid like a sponge, causing it to swell. This can be damaging to a seal, since excessive swell can cause premature failure. Chemical compatibility is extremely important during the material selection process to ensure your material will not react when introduced to specific chemicals.
With exceptional chemical resistance, Viton® offers swell resistance in high octane and oxygenated fuel blends. This gives Viton® superior performance abilities in Ethanol/Methanol blended gasoline applications. It’s important to note, however, that standard grades of Viton® do not offer the same resistance to steam and ethanol fuels and should not be used in these applications. Base resistant grades also offer improved resistance to amine based oil protectants found in new transmission oils.
While Viton® is resistant to a long list of chemicals, it is not recommended for exposure to:
Ketones
Amines
Low molecular weight esters and ethers
Nitro hydrocarbons
Hot hydrofluoric or chlorosulfonic acids
Skydrol® fluids
In contrast with its high-temperature resistance, Viton® does not retain flexibility at low temperatures, so it is not recommended for low-temperature applications.
With intense versatility and resistance properties, Viton® is typically the right material choice for more heavy-duty applications. Commonly employed in various gasket, o-ring and other rubber sealing solutions, Viton® has become a reliable material for automotive seals, transportation fuel applications and aerospace seals, pumps and valves.
Tweet us @AppleRubber to continue the conversation.
Everything You Need to Know About Viton®
was last modified: by