Phlogopite
Phlogopite is hydrous magnesium aluminum silicate
having the chemical formula H2 KMg3 Al (Si04)3.
It varies in color from light silver to dark brown or amber, and is classified
according to its shade, viz.; silver-amber, dark-amber, light-amber and wine-
amber. Phlogopite is not transparent but only translucent and is softer then
Muscovite and less resistant to outside chemical action but has greater heat
resistance. It can withstand temperature up to 1000 °C (1800 °F) without
appreciable dehydration. Because of its higher thermal stability, Phlogopite
mica is considered more suitable for applications where the high resistance to
heat is required.
Also know as Amber Mica, is more stable at higher temperatures up to 1000 °C. However, the higher dissipation factor and lower dielectric strength of Phlogopite prevents it from being used in capacitor applications. Phlogopite is used mainly for insulation in transformers, motors, and soldering irons and as insulating washers or discs. The thermal conductivity of Phlogopite is about the same as that of muscovite.
Phlogopite mica provides a higher heat resistance with a thermal decomposition temperature as high as 800 ° C. In addition, they perform excellent flexibility.
It is
not available in uniform large sheets hence primarily suitable for the
manufacture of mica paper laminates for use in high temperature applications
like Fire Resistance Tapes, Wire Winding Cards, Commutator Segments, Gasket
Materials, electric soldering irons, etc.
