Air bubbles in the ink. It is mostly caused by improper formulation of inks. When we add additives or solvents to stir, a small amount of air bubbles will be mixed in the ink. If you let it go, the lower viscosity ink will naturally defoam, and the higher viscosity ink. It cannot be naturally defoamed. Although some air bubbles will be eliminated naturally during the printing process due to the swivel chair of the ink, some will become larger and larger. Therefore, in order to completely remove the air bubbles in these inks, we need to add about 0.1% to 1% of defoamer in the ink, but pay attention to the appropriate amount, otherwise it will be too late and new bubbles will be generated.
In addition, it should be noted that when the ink swivels, it foams in time, but the fluidity and wetness of the ink on the surface of the main substrate are good, and the air bubbles on the surface of the printing ink film will gradually disappear, eventually forming a flat printing ink film. On the contrary, if the ink bubbles are not eliminated, the film surface of the final ink will be uneven. Ordinary ink will be defoamed due to the effect of the screen when passing through the screen. In order to make the ink have a better defoaming effect, it is better to use some hot water or boiling water when stirring.
For some transparent red, transparent blue, and transparent green inks. Because the amount of organic pigment in the particles is reduced, the bonding material of this ink has the characteristics of easy foaming, but if we add some detackifiers, tackifiers or thinners, it can also make it stable. Highly flexible and adaptable ink.