During the operation of the sander, the particles that are not crushed are thrown to the wall of the sander cylinder by centrifugal force. Static ring is also called gap ring or scraper, the inner scraper (moving ring) is installed on the discharge screen ring, the outer scraper (static ring) is installed on the front end plate of the cylinder body, the two form a certain gap discharge, play a role in stopping the grinding medium and screen. Static ring selection of tungsten carbide material, high temperature resistance is not easy to deformation and wear, corrosion resistance and impact resistance, can effectively reduce machine maintenance costs, is the best choice for high-end machines. It can be customized.