The application areas of the different sealing materials are very broad, from fuel technology to alcohol-based hydraulic fluids to food processing. Since all materials have different advantages and disadvantages, there is a separate material for practically every application.
For example, some seals swell on contact with fuels and become brittle, others are attacked by alkalis or wear quickly under mechanical load and force. In this section you will learn which sealing materials are suitable for your application.
Oil-Resistant Sealing Materials
Oil-resistant sealing materials must retain their elasticity when in contact with oils, greases and hydrocarbons and must not swell. NBR seals (e.g. Perbunan) and Teflon or FKM are ideally suited for such applications. In the case of mechanical stress, seals with a fabric insert or so-called compounds with glass fibres, bronze or carbon are used.
Fuel Resistant Sealing Materials
Fuel-resistant sealing materials largely coincide with oil-resistant materials: NBR, Teflon and FKM. However, mineral oil processing also uses aromatic-rich raw materials and fuels such as petrol and diesel are much more volatile and combustible, so that special material qualities are used. These ensure special tightness, fuel resistance and load capacity.
Sealing Material for the Food Industry
The modern food industry also requires seals in its equipment, for example, in the bottling of mineral water and fruit juices. These seals often need to withstand rotations and rotational movements.
Moreover, the highest standards of health safety and food-grade quality are demanded, which are also regulated by authorities. Many materials are available in food-grade versions. These include, for example, NBR, EPDM, FKM, or PU, which are often manufactured in special colors specifically for the food and pharmaceutical industries. Silicone and PTFE are generally considered suitable for food applications
Weather-resistant sealing materials
Seals are utilized not just indoors, but also outdoors. In such environments, they are exposed not only to process media or the materials being transported but also need to endure abrasive dust, wind, rain, ozone, air, temperature fluctuations, and UV light.
Silicone, EPDM, Teflon, and FKM have been established as sealing materials resistant to weather conditions.
Heat-resistant sealing materials
Many industries operate high-temperature plants in which an increased ambient temperature is to be expected (e.g. metal processing) or process heated raw materials (chemical industry). This fact must also be taken into account when choosing sealing materials, as costly sealing defects must be avoided.
Silicone, PTFE and FKM are particularly heat-resistant, but also graphite and mica materials in flat gasket technology. The specific selection must be made taking into account the other requirements (mechanical stress, pressure, resistance to oils, acids, alkalis)
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