Application of Flexo Ink Spot Printing In Tobacco Packaging

Water-based ink is one of the main factors affecting the quality of flexographic printing. Especially in cigarette packaging, it is a factor that cannot be ignored. The following describes the matters that should be taken into consideration when using flexo-printed spot ink in cigarette pack printing.

1. Before printing

(1) Ink shall be sealed and stored at a temperature of 15 to 25°C and a relative humidity of 65% to 70%. In addition, according to the ink shelf life, we must also reasonably purchase and store ink. If you do not have the above storage conditions, you can also use short-term procurement of storage methods, put ink on the printing machine 3 days before use.

(2) Since the spot color inks are made of two or more primary color inks, each spot color ink must be prepared one day before use, and the primary color inks and the spot color inks must be measured. The pH and viscosity are used as technical parameters for analysis.

(3) The ink needs to be fully stirred for two hours before being put on the machine. About half an hour is needed for stirring. The PH value and viscosity of the ink are measured in the first half hour. According to the printing environment and other factors, the pH and viscosity are adjusted so that the ink is stable in performance. The best results.

2. Printing

(1) When each shift is inked, the newly deployed ink should be used. After about one hour, that is, after the performance is relatively stable, the previous ink remaining can be added.

(2) As the thixotropy of the ink is large, it is necessary to add an appropriate auxiliary agent to adjust it at intervals, for example, stabilizers, retarders, pH adjusting liquids and other additives. The specific interval and amount of time should be determined according to the specific circumstances, control the PH value and viscosity of the ink in the printing process, so as to maintain the best performance.

(3) Due to spot color inks undergoing a long-time printing process, their hue may change slightly, which requires the operator to fine-tune the inks according to the color difference to ensure that the color difference is within the allowable range.