Perfluorinated rubber
Perfluoro ( abbreviation FFKM or FFKM ) or perfluoroelastomer is a fully fluorinated elastomer . Chemically, it is very similar to polytetrafluoroethylene (PTFE). It is mainly used where very good thermal and / or chemical resistance is required.
Manufacturing
By using special perfluorinated (i.e. completely hydrogen-free) monomers and the corresponding compounding and processing techniques, materials with rubber-elastic properties can be produced that come very close to PTFE in terms of their media and thermal resistance. The chemical and thermal resistance of these elastomers essentially depends on the type of crosslinking (peroxidic, bisphenolic or triazine crosslinked) and the degree of crosslinking. Therefore, there are sometimes serious differences in thermal and chemical resistance (e.g. with regard to water vapor and amine resistance).
properties
FFKM can be used between −20 ° C to +325 ° C. Special compounds (mixtures) can be used up to over +325 ° C or down to −30 ° C under certain conditions. The specification of the low temperature in particular relates to the static application. For dynamic use, it is recommended to orientate yourself on the TR-10 point or to add about 10 K to the lowest temperature.
use
FFKM is used in particular as a sealing material. Because of its comparatively high price per kg, its use is restricted to applications in which it is in contact with very aggressive media . It is used particularly in areas where there are high safety or cleanliness requirements or where possible high accident costs justify its use. This may for example in the chemical , the oil-producing and processing industry, the apparatus and power plant construction , the semiconductor -, the food industry or in aviation and space travel be the case. In these areas, certain processes can only be implemented by using this high-quality elastomer.
Chemical resistance
Perfluoroelastomers are the most resistant elastomers to aggressive media, which is noted in appropriate lists. Such a resistance list contains an evaluation of the chemical resistance to various operating media for various elastomer qualities, including FFKM. This information is based on tests and information from suppliers and users. Due to the different application conditions and composition of the media, this information is only to be regarded as a guide, it is not binding and must be checked on a case-by-case basis. All data refer to room temperature , unless otherwise stated.
swell
- ↑ resistance list cog.de .
- ↑ Resistance list cog.de (PDF; 353 kB).