Vermiculite
Vermiculite is a clay phyllosilicate that expands through heating. The expansion process is called exfoliation and is carried out in special ovens dedicated to this purpose. It is used for thermal insulation at high temperatures, refractory insulation, acoustic panels, etc. In friction materials it contributes to noise reduction.
Tags: ABRASIVES AND ABRASIVE GRINDERS, FRICTION MATERIALS, inorganic fillers