摘要 |
A printing machine for recording an image on a recording medium with marking particles, wherein process of making marking particles includes a method for dispersing pigment aggregates in a solution. The method employs an ultrasonic device to efficiently breakup particle agglomerates by driving the ultrasonic signal over a small range of frequencies around the acoustic slow wave frequency of the saturated agglomerate. At this frequency, the fluid vibrates out of phase with the solid and is forced out through the pore structure in the agglomerate. This relative fluid motion to exert high viscous stresses at the particle-particle contact points which leads to fracture of the agglomerate.
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