Polishing is mainly to meet the needs of optical skills and the beauty of the workpiece, which can increase the beauty of the workpiece. At the same time, the threshold of entering the market is favored by consumers and will increase the sales of your products. Cleaning is because in the process of mold production, there will inevitably be residual raw materials, water and other substances, which may be oxidized and rusted together with mold steel. This is harmful to mold, so it needs cleaning. All of the above are from Baidu Encyclopedia.