Before anodizing, aluminum profiles need to undergo sandblasting pretreatment. Sandblasting is an operation method that uses purified compressed air to spray dry sand onto the surface of aluminum products, thereby removing surface defects and presenting a uniform and matte sand surface on aluminum profiles. Sandblasting can remove burrs, casting slag, and other defects and deposits on the surface of aluminum profiles. After sandblasting, aluminum profiles will present a uniform and relatively smooth surface. Spraying with quartz sand will result in a light gray surface. If some part of the surface of aluminum profiles are protected before sandblasting, the sprayed areas will be dull and the protected areas will be bright, it will present artistic patterns on the surface of aluminum products and have a certain decorative effect. The surface protection effect of aluminum profiles that have undergone sandblasting pretreatment before anodizing will be further improv…