The grinding and brushing treatment of the substrate is to remove the dirt through the dual functions of the dissolution of alkali washing solution and the mechanical friction of the brush. The grinding and brushing treatment of color coating production line is designed to be mechanical, and the grinding equipment is also called brushing machine, which is usually composed of rotating brush roller, brush roller storage box, brush roller electric control device and alkali spray pipe circulation systemThe grinding and brushing process is generally set between the primary and secondary degreasing sections. The special brush roller material is used to grind and brush the upper and lower surfaces of the substrate with the same or opposite rotation direction as the running direction of the steel strip. Through the friction generated by the high-speed movement of the brush and the substrate surface, the dirt and rough oxides on the substrate surface are removed, and the substrate surface is smoothThe mask is active.There are usually two types of brush roller, compression type brush and bristle type brush. Compression type brush is a kind of brush that uses silicon carbide or alumina abrasives with very fine particle size to adhere to nylon wire, and then the nylon wire is made into fiberboard or cushion. After curing, the nylon wire is cut into a section of circular cylinder sleeve and installed on a roller core to make brush roller. The bristle brush is made of nylon wire containing silicon carbide abrasive. Abrasive particle size is different, the purpose is also different, two kinds of brushes have their own advantages and disadvantages. Because the abrasive grain size of compression type brush is very fine, and the pressure of brush roller on the surface of the plate to be brushed is relatively low, the surface of the substrate to be brushed is uniform. Its disadvantage is that the nylon wire is thin, easy to tear, and short service life. The outstanding advantage of bristle brush is that nylon wire has good wear resistance, so it has a long service life, which is about several times as long as compression brush. However, this brush is not suitable for treating thin plate substrate, which not only causes poor treatment effect, but also causes substrate curl. In order to prevent nylon filament from overheating and melting in the process of using brush roller type brush washer, alkali liquid should be continuously sprayed on the plate surface for cooling and wetting.