The adhesion of the sand to the surface is flexible bonding conductors. The surface is mostly paper, cloth, fiber and plastic film. And the size of a grain of sand is very rough until to the size of a..

Sand Paper, Abrasive Flap DicsThe adhesion of the sand to the surface is flexible bonding conductors. The surface is mostly paper, cloth, fiber and plastic film. And the size of a grain of sand is ver..