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The Difference between FFKM and FKM


An issue we have been sometimes asked is, just what is the difference between fluoroelastomer (FKM) and perfluoroelastomer (FFKM) components? With this blog media, we examine the distinctions between these two sealing materials, together with the advantages and disadvantages.
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FKM – Fluoroelastomers
Just as with lots of manufacturing breakthroughs, fluoroelastomers had been borne out of necessity. These were devised during WWII for an antidote for the leaky nitrile seals that affected the aircraft of the time. This brought about the development of fluorinated polymers whose chemically inert Fluorine-Carbon bonds provided a succeeding mixture of low-temperature effectiveness and high chemical substance level of resistance.

On the late 1950 year, FKM type 1s and 2s had been commercialised. Offering elevated chemical type level of resistance, the fluorine content material enhanced significantly from around 26.7% to 66%-68%. Recently, polymer style consistently increase because of a greater knowledge of the order in which monomers are polymerised and also the impact that has on the end product.

Advantages of FKM
Excellent mechanical attributes, enhancing sealing efficiency with very good compression set.
Naturally more resistant to burning off than non-fluorinated hydrocarbons.
Perfect for explosive decompression, CIP, SIP and FDA.
Great gasoline as well as fluid permeation resistance.
Fantastic weather capability and also ozone amount of resistance.
Huge temperatures range (- 45°C – 204°C).
High density and also high quality feel
Outstanding chemical resistance.

Disadvantages of FKM
Less chemically resistant just as FFKM to chemicals yet still excellent for most purposes.
Lesser temperatures array to FFKM’s but nevertheless a lot better than various other elastomers.
Selecting the wrong FKM for an program can lead to rapid failure.
Ought not to be used in combination with molten or gaseous alkali materials.
Higher cost you than other non-fluorinated hydrocarbons.
Might swell significantly in fluorinated chemicals.
Low-temperature grades are also quite really expensive.

FFKM – Perfluoroelastomers
Via the 1960s, there had been a growing desire for a polymer that was in fact far more chemically protected as well as had higher temp capabilities. Perfluoroelastomers ended up the natural conclusions, combining the chemical substance amount of resistance of PTFE with the versatility as well as resilience of normal FKMs. Originally, this next phase of elastomer technologies was almost exclusively the preserve of space programs and chemical operations. Nevertheless, FFKM had been soon appreciated by the wider manufacturing community, the moment its valuable properties became well-known.

These days, FFKM is a typical fixture on the aerospace and also auto businesses, among numerous others. Even though polymer structure has always been largely unchanged since the introduction of perfluoroelastomers, the polymerisation operation features experienced a operation of refinement over the many years and also FFKM materials can be created as part of a better, environment friendly creation method.

Advantages of FFKM
Very good mechanical attributes, bettering sealing efficiency.
Suited to incredible decompression, CIP, SIP as well as FDA.
Superb fuel as well as fluid permeation resistance.
Outstanding weather conditions capability and also ozone amount of resistance.
Self-extinguishing and also non-flammable in oxygen.
Broad temp array (-55°C – 330°C).
Great chemical level of resistance 
High Density.

Disadvantages of FFKM
Energy coefficient greater than many other elastomers, so seal housing size may require adjusting.
High cost you, thus generally utilised when nothing else elastomer is appropriate.
Ought not to be used with molten or gaseous alkali metals.
Can swell significantly in fluorinated solvents.

Thus, do you know the difference between FFKM vs FKM? Logically, FFKM supplies a greater degree of adaptability than FKM. It’s a lot more chemically resistant and also can stand up to a larger array of working temperatures, presenting highest service temperature of up to 330°C. And so, if your request calls for the highest quantities of results, then FFKM could – theoretically – be the ideal pick of sealing material. In which case, our special FFKM compound materials range of perfluoroelastomers offers top in class functionality.

Nevertheless, along with here's the heart on the subject, in case finances are a decisive consider your decision-making method, then simply we may possibly point you in the direction of FKM. When your demands for chemical and also temp resistance are not as onerous, then FKM can offer a lot of of the exact rewards as FFKM – just at the slightly less expensive. It’s still much more chemical, weather, ozone, natural gas as well as liquid resistance than most other elastomers. Like FFKM, FKM is also suitable for explosive decompression, CIP, SIP and FDA applications.

Both demonstrate very similar drawbacks too, in terms of swelling in fluorinated chemicals and incompatibility with molten or gaseous alkali alloys. Bearing that in mind, along with the risks of fast failure connected with choosing drastically wrong quality of FKM, it is important to look for the guidance of a technological specialist here at sunshine Polymer Solutions to be sure that your sealing solution is designed while using the accurate elastomer for your distinct application demands.