During the printing, there is a lighter crossband on the picture after cleaning the printheads. Especially for the one color or two color. The customer who use the up and down arrangment with xaar 128 printhead came across this things.
About the reason, about the machine constuction, most happened on the printer which is up and down arrangment with 4 colors. The ink is the volatile liquid. Quick drying, long time cleaning printheads and the strong permeability make the former ink and the current ink very different to mixed again.
The thing also happened in the experienced printing companies. The best way is that check the printheads before printing, if it necessary, please cleaning it. Don't cleaning the printheads during printing. If it is necessary to cleaning the printhead during the printing,please clean it quickly. The other way is keep the higher mositure indoor.
For this questiones, the printer factory could solve it. The way is slowing down the volatilization speed and prolong the drying time. The drying speed lower then the ink layer will be stick up. So we have to add the ink adhesion to ink. And the cost will be higher.
