A mixing paddle configured for use with a gravimetric blender. The mixing paddle has a first rotor; a second rotor spaced axial from the first rotor; and at least one mixing blade disposed between the first rotor and the second rotor. The at least one mixing blade of the mixing paddle includes an inner edge having a first sloped portion and a second sloped portion directed inward toward a middle portion of the at least one mixing blade. The mixing blade is configured to be narrower in the middle portion between the outer edge and the inner edge than at a first end and second end.