Abstract
The flowability of toner has been evaluated by the vibrating tube method. Twenty-six kinds of test toners were prepared by adding silica particles of 8-100nm in average diameter to the resin particles of 7μm in average diameter under various mixing conditions. In the flowability tests, the frequency of vibration was kept constant; the amplitude of vibration was increased at a constant rate for 100s, and the mass of particles that were discharged from the vibrating tube was automatically measured every 1 s. To evaluate the flow stability of toner, the measurements were repeated 7 times for each test toner. The basic features of the flowability were evaluated by the values of the total mass of toner discharged and the critical vibration acceleration to make the discharge. In addition, using the flowability profiles showing the relationship between mass flow rate and vibration acceleration, the details of the flowability of toner were characterized. A series of experiments showed that the vibrating tube method has the advantage of the short-time repeated tests and can evaluate the variation of the flowability arising from the small difference in the toner preparation conditions.
