ABSTRACT
The roll mill (also called the “velvet roll mill”, or “dodder mill”) separates seed by differences in surface texture and shape. It has become known universally as the dodder mill, since the separation of rough dodder seed from smooth lucerne (alfalfa) seed is a common use for this machine. Roll mills are effective in separating seed with a rough seed coat or sharp angles from smooth seed. The smooth-surfaced seed are not affected by the knap or roughness of the fabric covering the revolving rolls, while seed with rough or jagged surfaces are caught by the rough-surfaced rolls, are thrown, and ultimately separated.
