FFKM offers sealing solution for hazardous applications

FFKM combines the chemical resistance of PTFE with the elasticity of FKM and features a fully fluorinated backbone that gives it exceptional chemical, oxidative and thermal stability. Here, Process Industry Forum speaks to TRP Polymer Solutions to find out more about FFKM’s impressive temperature range capabilities.

High seal integrity and improved safety

FFKM (perfluoroelastomer, to give it its chemical name) is the ideal material for demanding applications that require high performance ‘O’ rings. The unique properties of this remarkable material provide the three-fold benefits of high seal integrity, reduced maintenance and operating costs, and improved safety.

Further benefits of FFKM include:

• Temperature range from -55°C to +330°C.
• Exceptional thermal resistance.
• Excellent chemical resistance.
• High reliability for static and dynamic applications.
• Extremely low permeability.
• Versions with FDA approval.
• Explosive decompression resistant compounds.
• Compounds with 50 to 90 Shore A hardness.
• Steam resistant compounds.

Near universal chemical resistance

A three-dimensional network structure is the foundation of any rubber-like material. In the case of perfluoroelastomers, a cure site monomer (CSM) is introduced to enable the formation of a three-dimensional network. Cyano-functional vinyl ethers are the most noteworthy CSM for FFKMs because they can be cured using a variety of curatives, including organic peroxide which results in a network with near universal chemical resistance.

Meanwhile, using the di-functional curative diaminobisphenol AF produces a benzoxazole crosslink, which results in networks that exhibit excellent thermal stability. Halogenated monomers (e.g. 1-bromo-trifluoroethane) are another common CSM for the manufacture of FFKM and are normally crosslinked using peroxide-based systems. However, peroxide curing can make FFKM more prone to thermal and oxidative degradation.

Using crosslink theory, TRP Polymer Solutions is able to develop grades of FFKM with wide temperature ranges that are capable of operating in extremes of temperature from -55°C to +330°C. As such, FFKM is an extremely useful material for sealing solutions in hazardous industries.

Low-temperature FFKM solutions

FFKM contains Carbon-Fluorine bonds which are generally regarded as the strongest single bond in organic Chemistry. It is this strength on an atomic scale that gives the material such high chemical, thermal and oxidation resistance on the finished product. FFKM is the only elastomer to contain no carbon-hydrogen bonds which are considered a weak link for thermal and chemical resistance.

TRP Polymer solutions’ low-temperature FFKM combines excellent chemical resistance and compression set resistance with outstanding low-temperature flexibility. It utilises unique monomer technology to extend the low temperature sealing down to -55OC whilst retaining its best in class chemical resistance.

For more information visit www.trp.co.uk.