The MI band heater from Watlow® is a high-performance heater. The band heater's performance and name are derived from Watlow's exclusive mineral insulation—a material with much higher thermal conductivity than mica and hard ceramic insulators used in conventional heaters.
A thin layer of the “high” thermally conductive MI material is used to electrically insulate the element wire from the inside diameter of the heater sheath. A thicker, “low” thermally conductive layer backs up the element wire directing the heat inward toward the part being heated.
The result is more efficient heat transfer, which lowers element wire temperatures and increases band heater life.