Precautions for the Use of Alcohol Water-based Inks:
Alcohol water-based inks should be stored at temperatures between 5°C and 30°C, with a shelf life of one year.
To maintain product characteristics, avoid low-temperature freezing or exposure to high temperatures.
Before use, thoroughly stir the ink, and cover and seal any remaining ink promptly after use.
During the printing process with alcohol water-based inks, if there is an extended downtime, clean the printing rollers and printing (screen) plates promptly. This prevents the volatile components, such as ammonia (amine), from evaporating in the ink system after restarting, leading to gelation or ink drying in the screen holes, which could affect print quality.
Adjusting ink viscosity should be based on machine speed and the type of substrate. Choose a solvent formulation or dilution according to the operator's instructions, especially considering environmental temperature and drying facility conditions (if the use of electromagnetic wave frequencies of 10150MHz for high-frequency dielectric heating is not ideal, consider using microwave heating drying methods with frequencies of 30030000MHz).
2. Inspection Methods for Alcohol Water-based Inks: The inspection methods for alcohol water-based inks include pH value testing, GB/T13217.1 (color testing), GB/T13217.3 (fineness testing), GB/T13217.4 (viscosity testing), GB/T13217.7 (adhesion testing), GB/T13217.5 (initial drying testing), GB/T13217.6 (coloring power testing), etc.
3. Troubleshooting Methods:
Poor Reproduction of Ink:
Causes: Low viscosity of the ink.
Solutions: Adjust pigment proportions, choose high-coloring pigments, ensure shallower printing (screen) holes during plate making, increase wetting and dispersing agent proportion, and consider adding anti-freeze organic solvents.
Formation of Gray Haze and Plate Sticking:
Causes: Slow drying of water-based inks, especially when printing at high speeds (150~300m/min).
Solutions: Improve printing plate precision, increase doctor blade pressure, and adjust compatibility between diluent and ink.
Slow Drying of Ink:
Causes: Slow evaporation of water, high viscosity, deep plate holes, or non-absorbent materials like plastic or aluminum foil.
Solutions: Increase drying temperature, switch to microwave drying, preheat packaging material, or raise environmental temperature.
Poor Adhesion:
Causes: Improper treatment of the substrate, wrong ink selection, excessive surfactants, low printing pressure, inappropriate viscosity, or excessive moisture or solvent in the ink film.
Solutions: Re-treat the substrate, choose suitable ink, avoid surfactants, increase printing pressure, use ink with higher resin content and lower viscosity, or control water content.