Separation of grains after its production is an important process. Separation of grains are done on the following basis-
Size
Length
Roundness
Density and specific gravity
Shape and surface texture
Aerodynamic property
Magnetic property
Colour
There are various separators developed nowadays. Let us discuss one of the basic separator i.e. Velvet roll separator
The velvet roll separator or roll mill separate grains on the basis of differences in shape and surface texture. It is a finishing machine and should be used only after cleaning and separation of grain from the chaff and trash. It is effective in separating grain with a rough seed coat or sharp angles from smooth surface grain.