FFKM

FFKM

FFKM is a perfluorinated high-performance elastomer material. Chemically, it combines the exceptional media and temperature resistance of PTFE with the elastic behaviour of a fluorinated rubber (FKM). This makes FFKM suitable for seals where conventional elastomers – and often even FKM – reach their limits.

Properties of FFKM

• Extremely high chemical resistance to acids, alkalis, solvents, aromatic and many halogenated hydrocarbons
• very good high-temperature resistance up to ranges where other elastomers undergo thermal degradation
• elastic behaviour similar to FKM with good resilience and low compression set (depending on compound)
• Very good resistance to many aggressive media in the chemical, petrochemical and process industries

The use of FFKM in fluorine-containing compounds or in elemental fluorine is not permitted under certain conditions – even perfluoroelastomer can be chemically attacked in these cases.

Temperature range of FFKM

Depending on the manufacturer and compound, FFKM types cover a very wide temperature range. Typical guidelines for static applications:

• Low temperature: depending on quality, approx. –20 °C to –40 °C
• Maximum temperature: high-quality compounds up to approx. +260 °C to +300 °C, individual special types up to approx. +320/+330 °C C

The exact limit values always depend on the respective material type, medium, pressure and the required service life.

Costs and application strategy

FFKM is a very cost-intensive material. It is therefore used specifically where:

• Downtime, leakage or contamination would be extremely expensive (plant availability, product losses),
• aggressive media (strong acids, oxidising agents, solvent mixtures) are present,
• high temperatures combined with high chemical stress occur,
• frequent media changes drastically reduce the service life of conventional seals.

Typical trade names include KALREZ®, CHEMRAZ® and SIMRIZ® – Kremer uses perfluoroelastomer under the name Krevolast, among others.

Typical applications of FFKM

Krevolast perfluoro-FFKM rubber is mainly used as a material for highly stressed seals and moulded parts

• FFKM O-rings and static seals in chemical, pharmaceutical and life science plants
• Seals in reactors, pumps, fittings, valves and compressors that are operated with highly aggressive media
• Seals in semiconductor and electronics manufacturing, where maximum purity and minimal outgassing are required
• Rotationally symmetrical moulded parts and sealing systems in high-temperature processes, e.g. in petrochemicals or gas processing

In addition to standard compounds, special compounds with specific approvals are also available, e.g.:

• NORSOK and explosion decompression approvals for high-pressure gas applications
• FDA-compliant or other food law approvals
• High-purity grades with particularly low extract and particle values for clean room and semiconductor processes

FFKM is therefore the material of choice when chemical resistance, temperature resistance and tightness at the highest level are required and the higher material costs are offset by longer service life and increased process reliability.

Disposal

According to the “Regulation on the European Waste Catalogue (AVV)”, the waste product from FFKM can be classified according to Chapter 7 “Wastes from organic chemical processes” and the waste code 07 02 99. This waste code stands for waste classified as non-hazardous.

They can therefore be disposed of in normal household quantities with normal household waste. Please use the container provided by your public waste disposal authority for residual waste as the appropriate disposal container.

Synonyms: FFPM, Kalrez®