Sandpaper is a paper or fabric on which a layer of abrasive powder of a certain grain is applied. This layer is added to paste compound and created by the method of mechanical processing of stone or chemically, for example, silicon carbide. There are many technologies for the production of abrasive powder for sandpaper. This stripping material can be used both for manual and machine grinding.
Sandpaper types depending on abrasive material
There are several varieties of sandpaper depending on the type of abrasive material. Each one has its own features but the principle of operation is the same: particles of a harder material remove particles of a softer one. With the help of sandpaper occurs rough and clean grinding of wood, metal from old paint or rust, glass, plastic and even ceramics if the abrasive has high thickness.
The following abrasive materials are used for the production of paper and fabric-based grinding instruments:
- Electrocorundum (alundum) is a mixture of swarf, low-ash carbonaceous material and bauxite agglomerate.
- Silicon carbide consists of silica and graphite. Ii is produced on Acheson furnace.
- Garnet is soft abrasive powder used for processing wood.
- Diamond, el’bor borazon material are the most durable abrasive powders used for processing stone.
How to determine the number of sandpaper
Sandpaper is divided by the graininess of the abrasive powder which is denoted by numbers and letters:
- According to the Soviet GOST (all-Union State Standard) 3647-80 marking is used: 6-H, 8-H, …, 63-H and 80-H.
- According to European designation ISO-6364: P220, …, P22.
There are coarse-grained and fine-grained sandpapers depending on the size of grain. According to the degree of processing there are very rough, rough, primary grinding, final grinding, final grinding of hard materials, polishing, metal grinding, fine polishing.
Recommendations for choosing sandpaper?
The main criteria of choosing sandpaper are the final requirements for the processed surface. If the surface is used under the mirror, then the material is chosen with the least graininess. If further painting is performed and there is no need for grinding, then sandpaper is chosen from 20-H to 6-H or P40-P220.