Sand washing is to use some alkaline and oxidizing additives to make clothes have a certain fading effect and old feeling after washing. If it is matched with a stone mill, it will produce a layer of soft frost-like fluff on the surface of the cloth, and add some softener to make the washed cloth soft, thus prolonging the service life of the clothes. Fabric will have the illusion of thickening, and sand washing is generally not recommended for thin fabrics.
Sand washing is generally used in industrial washing machines for puffing and sand washing softening, centrifugal pump dehydrators for dehydration, and drum dryers for drying goose down in knitting mills.