Epworth has been THE name in ball mills for over a century.

The ball mill is a cylindrical container with journals at it's axis. The cylinder is mounted horizontally on journal bearings partially filled with grinding media (pebbles, ceramic balls or rods, or metallic balls). The product to be ground is added and the mill to lift the media charge to one side of the cylinder and cause the media to roll, slide and tumble back down to the lower side.

To prevent slippage of the media charge inside the mill, baffles or "lifter bars" are attached to the mill cylinder which assist the lifting action of the mill. These bars are made of abrasion resisting alloy steel in steel ball mills or are formed by ceramic bricks in ceramic lined mills.

Pigment particles in the mill base (product) are caught between the tumbling media and are subjected to both impact and intense shear action which causes the required dispersion effect.