The engineering label FKM is a designation, a term that describes a group of durable fluoro rubbers. Branded as Viton, the synthetic material is a capable gasketing rubber. Consider the superior high and low-temperature resistance properties here, the aptitude for enduring the kind of chemical attacks that would quickly lay waste to a standard gasketing solution. FKM endures, even when corrosive fluids attack.

Hangs Tough When Caustic Fluids Attack

Classed by American engineering groups as a specialized fluoroelastomer category, FKM compounds are designed to provide outstanding material durability. The ASTM (American Society for Testing and Materials) appraised synthetic holds firm and functions without issue when a contained fluid is boiling hot or freezing cold. Corrosive solvents and caustic chemicals pass through the gaskets without eating away the rubber. Even ozone can’t undermine the toughened properties of fluoropolymer seals, nor can the lubricating or hydraulic oils that are known to cause seal fatigue.

Loaded with Upper-Limit Endurance

Granted, most gasket families are fabricated from the ‘right stuff,’ but this gang of rugged rubber compounds can’t match the elastomeric characteristics of Viton, a known FKM. For this synthetically enhanced polymer form not only resists such challenges, it retains the original shape of the gasket. That’s an important feature. After all, gaskets can function when they’re exposed to caustic fluids, but few of these materials have the structural strength to entirely defeat such form-damaging influences. Exposed to such corrosive fluids, non-fluoride gaskets swell and distort. As for a comparable FKM compound, this synthetic sealing material won’t collapse.

Determining Specific Applications

Picture a Viton gasket handling 200°C of vessel boiled heat. Then, out in a cryonics facility, the same FKM gaskets are capably handling -40°C of super-chilled fluid. Meanwhile, aerospace applications employ these fluoroelastomers in their hydraulic systems and lubricant lines. The oil doesn’t impact the gasket, so high-altitude wing flap operations are safeguarded. Biofuels or regular fuels, chemical plants or oil refineries, the gasket material properties of an FKM based seal are well recognized. Still, as with any other polymer, there are different types of FKM on the market. Know specific flow conditions before sourcing a potential synthetic rubber product, one that’s based on this robust synthetic rubber.

FKM gasket material properties highlight some seal challenging applications. In aerospace technology, the fluoropolymer seals install as ideal high-altitude, cold climate gaskets. They also channel lubricating oils and hydraulic fluids. At the other end of the spectrum, FKM gaskets operate as high-endurance ‘O’ rings and general application seals in the most caustic industrial settings, even those that channel highly corrosive acids.

Even though the label may seem unfamiliar, PTFE gasket materials exist throughout the food sector. Sure, you’re not going to see PolyTetraFluoroEthylene promoted in many kitchen brochures, but what about Teflon? That’s just another label for this chameleon-like material, a brand name that’s well-known as a non-stick cookware coating. As for PTFE as a gasket material, what benefits make Teflon a superior flange sealant when the food industry comes calling?

PTFE Gasket Materials: Scouring for Benefits

Well, non-stick benefits aren’t relevant here, but what about a talent for temperature resistance? PTFE is fabricated to endure when the fluid temperature hits 200°C. Considering the elevated temperatures found in the various food industries, that’s an important property. Furthermore, the gaskets will maintain their key mechanical characteristics when they’re called into service in a freezer. Approximately minus 70°C of frigid cold won’t trouble a Teflon seal. Of course, several other gasket families are similarly gifted. What about chemicals, then? Aren’t corrosive chemical compounds an issue in this industry?

Dealing a Blow to Corrosive Compounds

If you’ve never considered the corrosive conditions in the numerous food industries, now would be a good time to start. Sure, there are caustic cleaning agents aplenty, but they’re not the compounds you should be worrying about. There are acids in fruits, plus more acids in the blood and soft tissues that break free of various animal products. If time has its way, those relatively weak fluids will break down a substandard gasket. PTFE seals endure, even when a concentrated acid or alkali seeps into the waste discharge line. Incidentally, this could be a pressure vessel construct, this scenario described here. After all, pressure vessels raise the boiling temperature of water, which means the contained food cooks faster. If that seal is sustained, no matter the pressure, temperature, or acidity of the contents, then all pathogens are killed as the dish concludes cooking in no time at all.

The densely woven carbon and fluorine atoms present a united front. In other words, that non-stick surface does not break down. This feature ensures biological inertness, so the food streaming across the PTFE gasket is not tainted or spoiled, no matter how tortured that sealing product becomes. Run a finger down those properties, past food neutrality, temperature and chemical resistance, and superior compressibility. Those features and functions make Teflon a natural choice for many industries, but it’s the food industry that really benefits from those material attributes. Finally, there are ‘filled’ Teflon variants, products that tune these food industry properties so that its food handling capabilities are maximized.