Water-based ink is one of the main factors affecting the quality of flexographic printing, especially in cigarette packaging, which can not be ignored is the following brief in cigarette packaging printing using spot color flexo ink matters should be noted.
● Preprint
(1) Ink should be sealed, its storage temperature is 15 ~ 25 ℃, relative humidity of 65% to 70%. Also, according to the ink shelf life, reasonable purchasing and storing ink. If you do not have the storage conditions can also be stored in short-term procurement method, three days before using the ink is placed next to the press.
(2) Since the deployment of the spot color ink is made of two or more colors of ink made of, so they requested that each spot color ink must be the day before the deployment of the good, and measure ink colors and deployment of a good spot color ink PH value and viscosity, as a technical parameter for analysis.
(3) Ink needs to stir two hours before the plane, about to be stirred for half an hour, half an hour before the measurement of ink PH value and viscosity, according to the printing environment and other factors, adjust the PH value and viscosity, so that stable ink performance, print achieve the best results.
● printing
(1) ink on every shift, you should use a new formulation of ink, about an hour later, after the performance is relatively stable, before once before adding the remaining ink.
(2) Since the ink thixotropy large, it takes time to time by adding the appropriate additives to adjust, such as: stabilizers, retarders, PH value adjustment fluid and other additives. Specific intervals and dosage should be depending on the circumstances may be, to control the printing process, ink PH value and viscosity, so that it remains the best performance.
(3) Since the spot color ink in the long printing process, it will be some changes in hue, which requires the operator to fine-tune the color ink according to guarantee color within the allowable range.