Ceramic insulators are ceramic materials used to insulate electrically-conductive materials or temperature-controlled enclosures. In the context of electrical insulation, ceramic insulators are usually limited to the insulation of electrically conductive materials on an industrial or municipal scale.
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Advantages and Disadvantages of Ceramic Insulators
When compared with other insulation methods, such as silicone, oil, and air alone, ceramic is superior in many ways. Ceramic is durable and provides better protection than the other methods in most cases. The only drawback to using ceramic is in applications that require a large amount of flexibility. The stiffness of ceramic makes it unsuitable for flexible applications. However, with computers, cell phones, tablets, and other small electronic devices, ceramic insulating products are highly efficient and reliable.
Different Insulators in Ceramics
Ceramics are versatile materials and can be shaped into solid insulation of any shape. Ceramic fibers can also be spun into high temperature insulation “wool.” Ceramic wool is an excellent insulator because it is easily placed around heating enclosures and prevents heat from escaping. Ceramics vary in their electrical and thermal conductivity. Aluminum nitride and silicon carbide, for example, conduct heat well, which does not make them suitable thermal insulators. If either material was used to insulate a heating enclosure, heat generated in the enclosure would be transferred quickly to the insulation and then transferred again to the area outside of the enclosure. Aluminum oxide ceramics are fair thermal insulators and are most effectively employed in low-heat insulation applications. Silicon nitride is better still as an insulator and zirconia is among the most effective ceramic insulators, transmitting very low levels of heat between itself and heating enclosures. Another important property of ceramics related to their capacity as insulators is their low thermal shock susceptibility. Thermal shock susceptibility is the tendency of a material to become damaged when exposed to frequently or quickly changing temperatures. Most ceramics are very thermal shock-resistant.
Applications for Ceramic Insulators
Typical applications for a ceramic insulator are on power lines, coaxial cable, and circuit boards. The insulators prevent problems like EM wave reflections, shock to human users, fire hazards, power surges, and short circuits.
The most easily recognizable ceramic insulators can be found at power substations and on electrical transformers suspended from utility poles. They are called bushings and are usually designed with several conic or circular tiers stacked on top of each other. These tiers are designed to keep water as far away from the center of the bushing as possible; this reduces the number of avenues by which electricity could be conducted in the case of a bushing puncture or fracture. In the context of thermal insulation, ceramic insulators are used to help maintain the temperatures of industrial ovens, art studio kilns and many other kinds of heat-generating equipment. This improves heating process efficiency while simultaneously preventing the unwanted transmission of heat, often in unsafe degrees, into workspaces. Ceramics are often good choices for heat and electrical insulation because of the electrical and thermal non-conductivity of some ceramic varieties.
New Uses for Ceramic Insulators
Ceramic is a unique material because not only does it hold heat for extended periods, it is easy to manufacture and form into a variety of shapes. In fact, ceramic insulators are so effective, that in many applications, if a ceramic insulator is used, there are no other factors necessary to keep power where it belongs.
With new technology, comes new uses for ceramic products and insulators. Electrical components like transistors and ICs, are compatible with the use of ceramic insulation. Even high voltage products like transformers and capacitors, air insulation combined with ceramic insulating products provide the ultimate protection and insulation for the product itself and any human users.