| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a bead mill which can shorten a time required for flattening and improve the magnetic permeability of magnetic particles.SOLUTION: An aspect of the bead mill of this invention, being a bead mill used for the flattening treatment of magnetic particles, includes a mill body, a rotary shaft part, and a projection group. The projection group comprises a first projection projecting from the rotary shaft part to one side in a radial direction and a second projection projecting to an exact opposite side of the first projection with respect to the rotary shaft part. A plurality of stages provided with the first and second projections are provided along the axial directions, where adjacent stages are arranged with a displacement of 90° around the axis. When the bore diameter of an agitation part is D, a length in the axial direction of the projection group is 0.165D or more and 0.185D or less, and a length in a projecting direction of the projection group is 0.25D or more and 0.27D or less. When the volume of the agitation part is V, a volume which is a combination of the volume of the first projection and that of the second projection is 0.0062V or more and 0.0072V or less.</p> |
