Silicone

Silicone is an elastomeric material used in industry and trade where temperature resistance, ageing stability and chemical neutrality are required. Typical applications are found in mechanical engineering, electrical engineering, medical technology and food processing.

Compared with conventional elastomers, silicone remains elastic over a very wide temperature range. At the same time, the material shows high resistance to UV radiation, ozone and weathering. These properties make silicone particularly suitable for permanently loaded sealing and moulded parts.

A further advantage lies in the physiological safety of certain grades. Accordingly, silicone is frequently used where there is contact with food or sensitive products.

Depending on the requirement, different silicone grades, hardnesses and processing forms are available. A targeted selection is decisive for the function, service life and cost-effectiveness of the component. For classification within the material group, the overview of elastomers provides a suitable basis.

Properties of silicone

Silicone is characterised by a combination of thermal stability, chemical resistance and lasting elasticity. These properties determine the use of the material in technically demanding environments.

Temperature resistance

Silicone remains dimensionally stable and elastic over a very large temperature range. Depending on the grade, the typical service range is between about −50 °C and +200 °C, and briefly above this as well. Silicone is therefore suitable for applications with strong temperature fluctuations.

Ageing and weathering resistance

The material shows high resistance to UV radiation, ozone and atmospheric influences. Mechanical properties change only slightly even with long-term use outdoors.

Chemical properties

Silicone is resistant to many chemicals, oils and greases. At the same time, the material reacts largely inertly and shows little interaction with adjacent media. Special grades are available for applications involving contact with sensitive substances.

Elasticity and recovery behaviour

Even at low temperatures, silicone remains elastic and shows very good recovery behaviour. This property is decisive for seals, profiles and moulded parts with repeated loading.

For applications requiring different resistance profiles, alternative elastomers such as EPDM or NBR come into consideration.

Silicone grades and versions

Silicone is available in different grades and versions. The selection depends on temperature range, mechanical load, media contact and normative requirements.

Standard silicone

Standard silicone is used for general technical applications where temperature stability and ageing resistance are the main priorities. Typical areas of use are seals, covers and moulded parts in mechanical and plant engineering.

High-temperature silicone

Special high-temperature grades are available for applications with permanently elevated temperatures. These silicones retain their elastic properties even under prolonged thermal load and are suitable for hot-air, oven or engine environments.

Food-grade and medical silicone

Special silicone grades meet requirements for contact with food or medical products. They are characterised by high purity and low migration and are accordingly used in sensitive areas.

Hardness grades and mechanical adjustment

Silicone is available in various hardness grades. Soft grades are suitable for flexible sealing, harder variants for dimensionally stable components. The choice of Shore hardness influences sealing effect, installation behaviour and service life.

Versions

Silicone is processed as sheet material, profile, hose or moulded part. Depending on the application, cut-to-size pieces or customer-specific geometries are used. An overview of related materials can be found in the elastomers section.

Areas of application for silicone

Silicone is used in numerous branches of industry where components are permanently exposed to thermal, chemical or environmental loads. The combination of elasticity, resistance and material stability enables versatile use.

Mechanical and plant engineering

In mechanical engineering, silicone is used for seals, covers and protective components that must withstand high temperatures or changing ambient conditions. Typical applications are housing seals, protective covers and flexible connecting elements.

Electrical engineering and electronics

In electrical engineering, silicone serves as an insulating and protective material. The material is used for cable sheathing, seals in control cabinets and vibration-damping elements.

Food processing

Special silicone grades suitable for contact with food are used for applications in the food industry. Areas of use are seals, conveyor technology components and flexible moulded parts.

Medical technology

In medical technology, silicone is used because of its material purity and resistance. Typical applications are sealing and connecting elements in devices and components with increased hygiene requirements.

Outdoor and environmental applications

Due to its high UV and weathering resistance, silicone is suitable for outdoor use. These include seals, protective profiles and components with permanent environmental exposure.

For applications focusing on oil or fuel resistance, alternative materials such as NBR may be appropriate.

Distinction from other elastomers

Silicone has its own property profile, which differs significantly from other elastomers. A targeted distinction facilitates the material-appropriate selection for the respective application.

Silicone and EPDM

Silicone and EPDM are frequently used in similar applications but differ in temperature behaviour. Silicone is suitable for significantly higher continuous temperatures and remains elastic even in the cold. EPDM offers advantages in hot-water and steam resistance and in dynamically loaded seals. Further details can be found on the EPDM page.

Silicone and NBR

NBR is used where oil, fuel or lubricant resistance is required. Silicone shows a different resistance profile here and is preferred for thermal or hygiene requirements. A technical classification is provided by the overview of NBR.

Silicone and FKM

FKM is suitable for applications with aggressive media and high temperatures. By comparison, silicone offers advantages in elasticity over a wide temperature range and under weathering-related load. For chemically heavily stressed applications, FKM is often the appropriate choice.

The systematic comparison facilitates selection within the elastomers material group.

Processing and delivery forms of silicone

Silicone can be processed by various methods and is supplied in different delivery forms. The selection depends on component geometry, quantity and technical requirements.

Sheets and cut pieces

Silicone sheets are used for flat seals, covers and insulating components. Depending on requirements, standard formats or dimensionally accurate cut pieces are available, which enable direct further processing.

Profiles and hoses

Extruded silicone profiles and silicone hoses are suitable for linear sealing, flexible connections and protective applications. Shape and dimensions can be adapted to the respective application.

Moulded parts

Silicone moulded parts are produced for complex geometries. These are created by compression moulding or injection moulding and are used in series applications as well as in technically demanding components.

Processing methods

Silicone is processed by, among other methods, pressing, extrusion or injection moulding. The chosen method influences dimensional accuracy, surface quality and economic efficiency.

Further information on individual solutions can be found in the rubber moulded parts section.

Selection criteria for silicone

The selection of the suitable silicone grade depends on the technical and operational requirements of the application. A systematic consideration of relevant criteria facilitates the material decision.

Temperature range

The planned service temperature range is a central criterion. Silicone is suitable for applications with permanently high or strongly fluctuating temperatures. The specific grade should be matched to the actual temperature profile.

Media contact

In case of contact with chemicals, greases or food, it must be checked which resistances are required. Special silicone grades are available for sensitive or hygiene applications.

Mechanical load

Pressure, movement and deformation influence the choice of hardness and component geometry. Soft grades offer high flexibility, harder variants higher dimensional stability.

Ambient conditions

UV radiation, moisture and ozone act on the material in the long term. Silicone is particularly suitable for applications with permanent environmental exposure.

Standards and approvals

Norm-compliant materials are required for certain areas of use. These include, among others, requirements from the food or medical technology sector.

For application-related special solutions, the rubber moulded parts section offers a more in-depth overview.

Frequently asked questions about silicone

What is silicone used for in industrial applications?

Silicone is used for seals, profiles, hoses and moulded parts where temperature stability, ageing resistance and elasticity are required. Typical areas of use are in mechanical engineering, electrical engineering, food processing and medical technology.

What temperature range does silicone cover?

Silicone is suitable for a very wide temperature range. Depending on the grade, continuous use is typically between −50 °C and +200 °C, and above this for special versions.

Is silicone suitable for contact with food?

Certain silicone grades meet the requirements for contact with food. These grades are characterised by high purity and low migration and are used specifically in food processing.

When is silicone suitable compared with EPDM or NBR?

Silicone is suitable for high temperatures, strong weathering exposure and hygiene requirements. EPDM is frequently used for hot-water or steam load, NBR for oil and fuel contact. A classification of the alternatives is provided by the material pages on EPDM and NBR.

In which delivery forms is silicone available?

Silicone is available as sheet, cut piece, profile, hose or moulded part. The selection depends on component geometry, quantity and application.

How is the suitable silicone grade selected?

The selection is made on the basis of temperature range, media contact, mechanical load and normative requirements. For complex applications, rubber moulded parts offer an application-related solution.