Prediction of Jetting Stability of Pigment Dispersions by Zeta Potential Distribution Measurement

Abstract

Jetting stability of thermal printheads is difficult to be predicted, since the thermal printhead makes scorch on the heater because of boiling inks on the heater for jetting.

In order to prevent scorching of the heater, it is effective to increase the surface potential of the pigment particles, but the conventional measurement method cannot eliminate the effect of Brownian motion of the particles.

Therefore, we developed a new method for measuring the zeta potential distribution, which eliminates the effect of Brownian motion. We also found that there is a linear relationship between the new index ζ_2% and the jetting durability. In addition, the relationship between the index of ζ_2% and the jetting durability can be interpreted based on the classical DLVO (Derjaguin-Landau-Verwey-Overbeek) theory.

These results suggest that the jetting durability can be predicted by measuring the physical properties for the development of new inks for thermal heads.