Power for Safe Electricity Grids - Wacker Chemie AG


Power for Safe Electricity Grids

An uninterrupted power supply is vital in modern-day society. Whereas industrialized countries must modernize and expand existing integrated grids, emerging economies need to focus on setting up higher-performance grids. Both groups require reliable and high-performance products for optimal supply security. Here, POWERSIL® XLR® is a key component ensuring the safety of efficient silicone composite hollow-core insulators and making their production more economical.

Wherever power plants, power lines and switching stations must be built or modernized, there is a demand for suitable high-voltage insulators and equipment. After all, reliable insulators for current-carrying components are indispensable for power distribution's operational reliability. Insulators that fail can give rise to flashovers and short-circuits, thereby triggering an automatic shutdown of the affected component within the power grid. That is why power grid operators and energy providers must have completely reliable insulators.

Functional Risk: Dirt Pickup

High-voltage grids require long-rod and hollow-core insulators. The latter are always used wherever an active electrical component or device needs external insulation. The insulators used in overhead power lines connected to high-voltage grids are exposed to the elements throughout their service life, which is roughly 40 years: temperature changes, UV radiation, moisture or soilant. These influences can impair their functioning and operation. Dirt on insulators poses a special threat because moisture might render it electrically conducting and cause pollution flashovers.

Disadvantages of Porcelain Insulators: Heavy, Fragile and Prone to Dirt Pickup

High-voltage insulators have traditionally been made from dark-brown or gray hard porcelain. Very good insulation properties, though heavy, fragile and prone to dirt pick-up. Disadvantages that silicone composite hollow-core insulators don't have.

Silicone composite Hollow-Core Insulators: Long-Lasting Protection Against Water and Dirt

Silicone composite hollow-core insulators consist of a glass-fiber-reinforced plastic pipe, fitted with aluminum flanges at both ends, that carries sheds made of an elastic polymer. This silicone surface is permanently hydrophobic and even capable of transferring its water-repellency to adhering particles of dirt: rainwater and dew simply roll off the silicone sheds in beads. Even if the sheds are exposed to the elements for years outdoors, there is no risk of pollution flashovers, because a continuous, electrically conducting moisture film cannot form. What's more, silicone composite hollow-core insulators are unbreakable, earthquake-proof and much lighter than their porcelain counterparts.

Low-Pressure Die Casting Requires very Low-Viscosity Liquid Silicone Rubber

Hollow core insulator after removal from the mold

Low-pressure die casting is ideally suited for industrial shielding with silicone. That requires very low-viscosity liquid silicone rubber. Conventional liquid silicone rubbers, on the other hand, are very viscous. The material can therefore only be injected at high pressure which, in turn, entails expensive injection molds. That makes the normally efficient process less economical – which is why the better, yet more expensive, procedure took a long time to establish itself on the market.

POWERSIL® XLR®: Better Products for Operational Safety

The breakthrough came in the form of POWERSIL® XLR® 630. The two-component, extra-low-viscosity liquid silicone rubber from WACKER offers a true alternative with its specific technology – XLR®, which stands for extra-liquid rubber. It embodies all the advantages of the two different rubber systems. Today, this innovative material is the preferred product for low-pressure diecasting of the protective silicone. Some 80 percent of composite hollow-core insulators in Europe are now made by low-pressure diecasting, and nearly all of the companies applying this process use POWERSIL® XLR®. Your advantage: better products for more economical processes and more operational reliability.

Would you like to learn how POWERSIL® XLR® liquid silicone rubber can optimize your application? We would be pleased to show you all of the advantages and possibilities for your specific needs.