... wet method 5.Pure biotite material Series: Muscovite, Phlogopite, biotite, sericite, wet ground and dry groundSize: 20mesh, 40mesh, 60mesh, 80mesh, ... are insulativity and heat resistance, which are perfect: 1). If mica's thickness reaches 0.015mm, its average breakdown voltage would ... 7kV, puncture strength would be 133- 407KV/mm. 2). When mica is heated by temperature of 100-600°C, its elasticity ...