Silicone Insulators

Fragile insulator materials

Insulators are used to protect power lines and high voltage transformers (bushings) and as surge arresters and cable accessories (junctions, cable ends). Often, glass (ceramic) insulators are used because of their low price but they are heavy and brittle. Elastomeric composite insulators are a good alternative because they feature:

  • Excellent mechanical properties that protect them from shocks during shipping and installation
  • Low weight (on average 80% lighter than glass insulators)
  • Reduced costs to transport, install and maintain

Silicone insulators are also better than EPDM (Ethylene Propylene Diene M-class) rubbers and other organic polymers because they are able to maintain their hydrophobic properties after contamination and corona discharges. This is the result of two combined effects: the reorientation of PDMS (Polydimethylsiloxane) chains and the regular distribution over time of low molecular weights to the surface of the elastomer.

Silicones also offer more to resistance to UV and extreme temperature fluctuations than organic polymers. For all these reasons, silicones are currently the best material for this application, in particular to comply with more rigorous international standards and specifications.

A partner to rely on for power lines regulation processes

For over 20 years, we have been developing many Silicone HTV (High Temperature Vulcanized) products for high voltage applications, including silicone insulators for current distribution and transmission, hollow core insulators for transformers, surge arresters and assorted cable accessories.

We custom design and deliver solutions that allow each of our customers to optimize their specific processes, while complying with national and international standards (e.g.IEC 62217, IEC 62039, etc.). This understanding of diverse markets and our flexibility have been the basis for numerous partnerships worldwide with leading companies in the field of high voltage equipment, including Sediver, Maclean, Dervasil, Nexans and many others.

Customer adapted ready-to-use insulator compounds

Elkem Silicones designs and produces custom compounds for each manufacturer’s requirements in terms of productivity, catalyst systems, shape requirements and the color shades needed in their markets. Depending on the final application, the tracking resistance of our HTV products is classified between 3.5 and 6 kV. To achieve these exceptional levels of tracking resistance while maintaining high levels of electrical insulation, we have been working on ATH (trihydrated alumina) properties and surface treatments, while optimizing cost effectiveness with different ATH grades. This way, the consistency of the final ready-to-use compound is adapted to each customer’s process.

Our range of silicone insulators are available in a variety of shapes and colors through our Mix&Fix Centers™, the Elkem Silicones compounding network.

Our experts are also available to advise you upstream and make sure that our products do exactly what’s needed in your specific manufacturing processes and markets. Downstream, we also provide all the information and certifications needed to comply with regulatory obligations.