Grind Media Density

Release time：2021-10-12

The bead grinding medium of the sand mill should be truly spherical, with narrow particle size distribution and low price.  In addition, three main factors should be considered: particle size, density and chemical composition.  The outlet of the particle size sand mill is provided with a filter screen, so that the dispersed slurry passes through and the sand grinding medium must be kept in the shade.  Therefore, the diameter of the bead must be larger than the diameter of the screen hole, experience shows that the diameter of the grinding ball should be at least half larger than the maximum aperture of the screen hole, otherwise the screen will often be blocked.  Because the beads in the grinding process inevitably wear, so the actual selection of grinding bead diameter should be appropriately enlarged.  Smaller beads should be used as long as they do not clog the sieve because they provide more grinding contact points, meaning that the pigment will disperse better as long as the beads provide energy.  Density for the commonly used vertical sand mill, the density of scattered beads is low, the trend of beads sinking and sinking to the bottom of the sand mill is less, the wear of beads and the wear of the sand mill is small, but it produces small dispersion force.  Therefore, for easily dispersed pigments and polymers of smaller pigments, can use smaller density beads, for difficult to disperse pigments and polymers of coarse pigments, should use high-density beads, at this time, the viscosity of pigment paste should be slightly higher, in order to reduce the deposition of beads affect dispersion.  Chemical grade for latex paint production, grinding often used grinding beads are glass beads, it is more transparent, is not very wear-resistant, will not lead to excessive wear of sand grinding machine, high strength glass beads also only show moderate wear.  The wear products of glass beads themselves are generally invisible and non-wear.  Most glass beads have about the same hardness and wear rate.