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Sealing technology manual for the process industry - FKM

oils and waxes, aliphatic and aromatic hydrocarbons, essen- tial oils, and at high temperatures. The material also has good properties in CIP/SIP media for continuous operation plants in the food and pharmaceutical industries. In cleaning pro- cesses, it must be taken into account that the use of alkaline solutions, acids and oxidizing media such as peracetic acid is restricted. FKM reacts very sensitively when used with highly oxidizing cleaning agents and disinfectants containing ni- tric acid, formic acid or peracetic acid. In any prolonged use in alkaline solutions, FKM also loses its stability. However, for short cleaning cycles, this material is still suitable. In the event of doubt, our materials advisory service can assist in finding an optimal materials solution for the individual re- quirements. FKM in the beverage and dairy industry FKM is recommended for both the processing and handling of pure citrus juices and for applications with concentrated essential oils and dairy products. However, a blanket recom- mendation for use in all flavors and their mixtures cannot be made, because this is an extraordinarily diverse and com- plex media group. But it is worthwhile to discuss the indi- vidual applications with Freudenberg’s materials technolo- gy experts since FKM is in many cases the more economical alternative to other material solutions. FKM in the pharmaceutical industry In the pharmaceutical industry, FKM is employed when non-polar solvents, aliphatic compounds, fats and oils are used. Amines and ketones, however, preclude the choice of FKM materials. FKM (fluororubber) is a high-quality material which can be adapted to different applications thanks to its variable composition. By polymerization of vinylidene-fluoride (VF) and optional use of variable proportions of hexafluoropropylene (HFP), tetrafluoroethylene (TFE), 1-hydropentafluoropropylene (HFPE) and perfluoromethylvinylether (PMVE), it is possible to pro- duce co-, ter- and tetrapolymers with different composition and fluorine contents between 65% and 71%. Thus, the material can be designed for different requirements in terms of chemical resistance and low-temperature flexibility. In the food industry, FKM is used in applications where tempera- tures above +140 °C (+284 °F) prevail in the process or where media are used which attack other elastomers such as EPDM or HNBR. General properties • Excellent temperature resistance • High chemical stability • Very good resistance to ozone, weathering, aging and ox- ygen • Excellent resistance to mineral oils and fats • Low gas permeability • Shows a very good resistance in non-polar media • Tends toward increased swelling in polar solvents, ke- tones and amines • Temperature stability from –25 °C to +200 °C (–13 °F to +392 °F) 70 FKM 37508, 75 FKM 38269 and 75 FKM 180497 Application profile Fluororubbers with a special composition of the mixture pro- vide excellent resistance in hot water, steam, and alcohols. FKM is very well suited for use in animal and vegetable fats, RULES AND STANDARDS 70 FKM 37508 75 FKM 38269 75 FKM 180497 FDA-compliant (CFR 21 Part 177.2600) + + + EU Reg. 1935/2004 EU Reg. 2023/2006 + + + + + + 3-A® Sanitary Standards Class I + + + USP Ch. 87 (in vitro) USP Ch. 88 (in vivo) Class VI – 121 °C (250 °F) + + FKM Elastomeric materials 40 RULES AND STANDARDS 70 FKM 3750875 FKM 3826975 FKM 180497

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