... are used as functional fillers or extender in the manufacture of plastics, paints,resins, thermal coatings, epoxies, mastics; ... and functionality. Cenospheres are environmentally: 100% recycledMade up of silica, iron and alumina, cenospheres have a size range ... sound proofing,thermal insulation, interior and exterior paints, injection molding of plastics, automotive brake linings, and are even used ...