What is the purpose sandpaper

Commonly known as sandpaper sand paper. One kind of material for polishing sandpaper. Sandpaper used for polishing a metal, wood and other surfaces to make them smooth and clean. Sandpaper usually deadlocked in the original paper from a variety of abrasive grit. The following is  abrasive manufacture an enormously Metal Machine Network Xiaobian to introduce what is sandpaper? What is the purpose sandpaper? What are the classification sandpaper?
 Depending on the abrasive material, emery paper, artificial emery paper, glass paper, and other. Dry sanding paper (wood sandpaper) for polished wood, bamboo surfaces. Waterproof abrasive paper (sandpaper) used in water or oil polished metallic or non-metallic surface. All with unbleached kraft paper pulp copied into. Paper tough, wear-resistant folding, and good water resistance. The glass sand and other abrasive substances such as gum adhesive with adhesive on paper, after drying.
Classification of sandpaper in actual use, the classification of sandpaper far from uniform. Accordance with the purposes of:
Sponge sandpaper: Suitable for sanding smooth sandpaper  part of a variety of materials can be.
Dry sanding paper: suitable for rough or polished some of the rough stuff, such as iron pipes metals.
Shuimo sandpaper: relatively thin texture, water mill grinding some texture sandpaper for the finer things, and is suitable for post-processing; mill grit sandpaper gap between its small, very fine grind is also smaller, and when used in conjunction broken water it will end with the cutting and grinding disc  water out, so to use with water, if the water take it very fine sandpaper dry grinding sand will remain in the gap, so that the surface becomes light sandpaper to reach its present some results, and dry sandpaper not so troublesome, it is the large gap between the sand particles are large very fine grinding out its grinding process due to the large gap causes Suimo will fall, so it does not need, and water together.
By product name stars: Wood sandpaper, or dry sanding paper; water sandpaper, ie waterproof sandpaper; iron emery cloth, is a dry abrasive paper, thick, polished metal surface as quickly as possible. Waterproof sandpaper
Waterproof abrasive paper [1], also known as mill or water sandpaper sandpaper, because when used in water flooding grinding or sanding is named, waterproof sandpaper is water-resistant and water-resistant treated paper or paper as the substrate, in order to paint or resin binder, corundum or silicon carbide abrasive to stick firmly to the substrate made of a grinding, the shape of a sheet-like and roll two kinds.