US Patent 7281768 Manufacturing method and apparatus of brush

A method of manufacturing a brush includes inserting bristles into bristles insertion holes, and implanting the bristles in a resin material. The inserting further includes preparing sleeves corresponding to cross sectional shapes and cross sectional areas of the bristles insertion holes; introducing the bristles into the sleeves; and independently inserting the bristles within each of the sleeves to the corresponding bristles insertion holes.