Product Announcement from Wacker Chemical Corp.
Porcelain and glass insulators are often used to insulate overhead power lines. However, these kinds of insulators can quickly get dirty in coastal areas and industrial regions with high air pollution, which may have serious consequences in terms of safety. Moist dirt, dust or salt deposits can impair the insulating capacity of such materials, due to electrical discharges or even so-called pollution flashovers. To avoid this scenario, glass and porcelain insulators must be cleaned regularly, which is complex and expensive.
That is why WACKER’s POWERSIL® product range for applications in the transmission and distribution (T&D) industry has, for many years, included specialty silicone coatings for glass and porcelain insulators. Silicones are not just excellent insulators, they are also highly hydrophobic (water-repellent). For insulators, this water-repellent effect plays a key role. It enables silicone coatings to reliably prevent the formation of wet pollution layers. Thus, the typical flashover scenario – wet film layer with an increased leakage current, dry band arcing, bridging of individual insulator sheds and finally the electrical flashover – is impossible.
With POWERSIL® 570 PLUS, WACKER is launching the world’s first insulator coating based on a patented silicone-in-water emulsion technology onto the market. The ready-to-use product is solvent-free and does not contain tin components. Its viscosity displays a strong dependence on its shear rate, which leads to perfect spray behavior. The emulsion coating can be applied in a single spray cycle in the desired final layer thickness.
POWERSIL® 570 PLUS adheres to ceramic and glass substrates without adhesion promoters and displays excellent hydrophobic properties. Insulators coated with POWERSIL® 570 PLUS pass the 1,000-hour salt-fog test as per IEC 62217. This test is considered the most important criterion for the safe outdoor use of electrical insulating materials in the T&D sector.