Coated abrasives are manufactured by applying a layer of abrasive grains onto a flexible backing material, such as paper, cloth, vulcanized fiber, or polyester film. A base coat of adhesive (make coat) binds the grains to the backing, and a second coat (size coat) is applied over the grains to secure them and provide structural reinforcement.
They are available in various forms, including belts, sheets, rolls, discs, and flaps. Coated abrasives are characterized by their flexibility, which allows them to conform to curved or irregular surface contours, making them ideal for finishing, blending, and polishing.
The spacing of the abrasive grains on the backing can be modified: open coat products have gaps between the grains to prevent loading (clogging) when sanding soft materials like wood or aluminum, while closed coat products cover 100% of the surface for aggressive cutting and finishing of hard materials.
Typical applications include flap discs for weld blending, wide belts for wood calibration, sanding sheets for automotive body prep, and vulcanized fiber discs for heavy-duty metal grinding.