Martin’s Rubber Company’s guide to Viton rubber
Viton® could well be the most high performance and durable rubber material that you’ve never heard of yet. PIF spoke to Martin’s Rubber Company to get the lowdown on this impressively versatile fluoroelastomer.
Even in the harshest environments, subjected to temperature extremes and harsh chemicals, Viton® fluoroelastomers perform extremely well. With that in mind, this rugged rubber is ideally suited for applications requiring hard-wearing O-rings, gaskets and seals.
Viton® elastomer properties
Viton® is a brand name of DuPont for its synthetic rubber and fluoropolymer elastomer, commonly used in O-rings and other moulded or extruded products. This family of elastomers comprises copolymers of terpolymers of tetrafluoroethylene (TFE), hexafluoropropylene (HFP) and vinylidene fluoride (VDF or VF2), vinylidene fluoride (VDF) and hexafluoropropylene (HFP) as well as perfluoromethylvinylether (PMVE) containing specialty polymers. DuPont were the first to really market this family of materials, so Viton® has become the most commonly associated name with this fluoropolymer family.
There are four families of Viton® polymers, and the fluorine content of these most popular Viton® grades varies between 66 and 70%.
The main grades are:
- A (Dipolymers of VF2/HFP), which has a fluorine content of 66%.
- B (Terpolymers of VF2/HFP/TFE), which commonly used for seals or gaskets and contains 68% fluorine.
- F (Terpolymers of VF2/HFP/TFE), which is used in oxygenated automotive fuels and has 70% fluorine content.
- Finally, specialty types (such as GLT, GBLT, GFLT & Viton® Extreme), which are used in automotive and oil exploration applications.
Benefits of Viton®
Compared to most other elastomers, Viton® is better able to withstand high temperature, while simultaneously retaining its good mechanical properties. Oil and chemical resistance are also essentially unaffected by elevated temperatures. Compounds of Viton® remain substantially indefinitely when exposed to laboratory air oven aging up to 204°C or to intermittent exposures up to 316°C.
Viton® grades also resist degradation from a wider variety of chemicals and fluids – including oils, fuels, lubricants and most mineral acids – than any other non-fluorinated elastomer. In layman’s terms, that means it provides the best fluid resistance of any commercial rubber. With its low permeability to such a broad range of substances, Viton® is known to deliver exceptionally good performance in oxygenated automotive fuels.
The rugged characteristics Viton® don’t stop there however. Because they also display good resistance to compression, even at temperatures that would make other non-fluorinated elastomers brittle. It is also especially resistant to atmospheric oxidation, sun, climatic conditions, fungus and mould. Furthermore, Viton® has good electrical properties (in low voltage, low frequency applications) and low burning characteristics.
Viton® rubber applications
Viton® is a durable material for O-rings, gaskets and seals, all of which can be specified and manufactured at Martin’s Rubber; either to your own bespoke requirements or as off-the-shelf parts. Viton® tubing is also commonly used in automotive, and other transportation fuel applications, involving high concentrations of biodiesel.
Types B and F (FKM- GBL-S and FKM-GF-S) have been proven to be more resistant to acidic biodiesel because this type of fuel is unstable and oxidising. There are many grades of Viton®, so it is still important to understand the requirements of the application and ensure that the right grade is used. So make sure you ask an expert at Martins Rubber before you make your final choice of Viton®.
Find out more about Martin’s Rubber Company’s Viton® products by speaking to them on 023 8022 6330, or email [email protected]
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