Abstract
The tribo-charging behavior between toner particles and carrier beads were studied by measuring the Q/M and Q/D spectra of toner mixing with ferrite carriers. Initially, the toner without extraparticulates were used. The Q/M values after tribo-interaction were found to always increase with mixing time, but it saturated when a critical time was reached. The saturation value of Q/M decreased with the toner concentration. The wrong-sign toner population also decreased with mixing time. When extraparticulates were added into the toner before mixing, the charging characteristic changed completely. The Q/M data were strongly dependent with the selection of extraparticulates, indicating that the tribo-charging process between the carrier and toner was overwhelmingly a surface interaction phenomenon. In addition, we found that smaller toner particles always contained lower charge per particle (q p ) which followed a linear dependence with the square of the particle diameter.