Why elastomers are so important

Elastomers play a key role in modern industries: from sealing rings, gaskets, and hoses in the automotive industry and mechanical engineering to medical technology and cable sheathing in electrical engineering, elastomers are essential functional materials.

Unlike thermoplastics and thermosets, they have a slightly cross-linked structure, which gives them exceptional elasticity and rubber-like stretchability. They can be stretched or deformed significantly and then return almost completely to their original shape. The properties of elastomers make them indispensable for components that require flexibility, damping, or sealing.

For technical decision-makers, elastomers are therefore an important component in the selection of materials—especially when it comes to reliability, safety, and durability in demanding operating environments.

The characteristic material properties of elastomers give them a special position among plastics:

• Elasticity and shape retention – malleable yet dimensionally stable
• Resistance to temperature, UV radiation, and chemicals – suitable for demanding environments
• Abrasion resistance and long service life – reliable even under dynamic loads

When it comes to flexibility, shock absorption, or sealing, elastomers are the material of choice. Elastomers have a slightly cross-linked molecular structure. This cross-linking is strong enough to prevent melting and flexible enough to allow rubber-like elasticity. Thermosets, on the other hand, are tightly cross-linked and therefore hard and brittle, while thermoplastics have no permanent cross-links and can be molded as desired when heated.

Thermoplastic elastomers (TPE) are a special case: they combine the processability of thermoplastics with the elasticity of classic elastomers. This opens up new possibilities in series production.

• Elastomers → vulcanized or chemically cross-linked, perfect for flexible, cushioning, or sealing applications.
• Thermoplastics → meltable, ideal for series production of molded parts.
• Thermosets → cure once, suitable for high-temperature-resistant components.

• Flexibility in design – adaptation to complex geometries
• Functional versatility – from sealing to vibration damping
• Cost-effectiveness – efficient to use, especially in series production
• Reduction of vibrations, noise, and leaks – crucial for durability and comfort

Elastomers are typically manufactured by:

• injection molding, extrusion, or compression molding
• vulcanization or chemical cross-linking – crucial for elasticity and resilience
• customized formulations and blends – tailored to requirements for hardness, temperature, or chemical resistance

HPF Minerals supports customers with advice and material expertise – especially when it comes to finding the optimal combination of elastomers with functional fillers and additives.

HPF fillers can further optimize the specific properties of elastomers. For example, HPF fillers enable the improvement of mechanical properties (Shore hardness, modulus of elasticity, tensile strength, etc.) and electrical properties (dielectric strength) as well as good to very good colorability of the elastomer.

Fluoroelastomers are highly specialized materials for the most demanding applications in engine and machine construction as well as in chemical plant engineering. They make seals resistant to various chemicals and very high temperatures.

TREMIN^® 283, a short-needled, silane-coated wollastonite powder, has been used successfully for many years as a functional filler with a focus on tensile strength and dimensional stability in fluoroelastomers for adjusting hardness. In fluoroelastomers, TREMIN^® 283 offers not only good reinforcement but also the advantage of colorable, light-colored compounds. These optimized fluoroelastomers are ideally suited for the above-mentioned applications under special conditions, such as high mechanical stress and high temperatures.

Fluoroelastomers reinforced with TREMIN^® 283 are characterized by the following properties:

• excellent dimensional stability
• very good dyeability
• high tear resistance
• high tensile strength

Silicone is extremely elastic, highly heat-resistant, hydrophobic, and has a high dielectric strength.

Unlike rubber, silicones retain their properties over a wide temperature range. Silicones are therefore used for seals, insulation, and molded parts that are subject to high thermal stress and have become indispensable in medical technology, the electronics industry, and the household. Quartz and cristobalite are inert and, unlike needle-shaped wollastonite and platelet-shaped kaolin, are rather round and compact due to their structure. In addition to the untreated types in the SIKRON^® family, surface-treated SILBOND^® types are also available.

Quartz is mainly used for seals and cables, in particular the SIKRON^® SF 600 grade and the coated variants SILBOND^® 600 TST and SILBOND^® 600 RST. The surface treatment of the filler ensures low viscosity during the processing of the silicone.

The use of this filler allows the electrical and mechanical properties of the silicone part to be specifically influenced (e.g., increasing the electrical insulation behavior).

The silicone polymers reinforced with SIKRON^® and SILBOND^® are characterized by the following properties:

• excellent tensile strength
• high tear resistance
• increased modulus of elasticity
• very good dyeability
• increased electrical insulation properties

The right choice of fillers enables a very high filling degree with the desired viscosity of the impression materials. This allows for maximum precision of the impression by minimizing reaction shrinkage. The very white cristobalite allows for excellent colorability and the desired elasticity or Shore hardness of the impression materials. From our product portfolio, we generally recommend the silanized SILBOND^® types.

We are always happy to answer any questions you may have about elastomers. Please get in touch –  we will get back to you as soon as possible.