A customer called today with a Mica Band heater that he said every time he used one of the heaters with in 10 minuets they would blow. He was buying the heaters from another company but decided to give me a go at it since I had just done a few specialty ceramic bands for him to use in a different application. The heater was a 4″ wide x 5″ long it has 460V and 2000 watts. As soon as he told me the wattage I knew what the problem was. He had way to many watts per square inch in the mica band that was only rated to have 1480 watts max.

After pausing for a second to do the formula to calculate watts per square inch. I let him know I had good and bad news the good news was that it was not his application causing the problem. The bad was that he would have to through all the rest of the mica bands he had ordered in the trash or use them on a different machine because they would not work.  What he needed was a mineral insulated band.

With a MI band you can achieve 70 watts per square inch. which is double that of a mica band at 45. He would be able to get to much higher temperatures a lot faster and sustain  them for as long as he needed. The Mineral insulated bands also have more longevity then mica bands. The only down side to the MI band is the lead time because they require a baking time it takes longer to build them. He decided to place the order  for 4 that way he would have two to run with and two as spares.