A grater screen is designed for the milling of particularly hard materials, which require a more aggressive milling action than a conventional round-hole screen. Typically these applications will require a square-bar impeller.
The surface of the screen is raised to create a rasp, giving more of a shearing action for breaking up the material. Typical applications for a grater hole screen include seeds, and hard products which are trying to be reclaimed, such as tablets or sweets. Failure to correctly identify the need for a grater screen can result in the generation of fines or can severely damage the screen.
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