Common problems and solutions of water-based ink printing

In recent years, the printing industry has gradually transformed to green and sustainable development, and green printing has become the main direction of the development of the printing industry

Water-based ink uses water as the main solvent, and does not emit volatile organic compounds (VOCs) during the printing process.

However, because water-based inks use water as the main solvent, they also bring some problems to their application during the printing process

01 gelation

Phenomenon: Due to improper storage or improper use of ink additives and solvents, the ink loses its fluidity and solidifies into a gel

Solution: Keep the ink tightly closed in a cool and ventilated environment, and use special auxiliary additives and solvents

02 Blurred outline

Phenomenon: The high-profile part of the printed product is blurred, the dots are blurred and the tone is lost

Solution: The pad should be adjusted evenly and evenly to adjust the printing pressure.

03 light ink

Phenomenon: The ink color is light and cannot reach the ideal color concentration
.
It is mainly manifested that the ink color concentration of the printed graphics and text on the cardboard is lighter, the tone is dim and not bright, which is mainly caused by the unsatisfactory viscosity of the ink.
If the viscosity is too low, the original ink should be replaced or remixed
.

Solution: The ink should be fully stirred before use.
If the ink quality is found to be poor, the good ink should be replaced, and the ink transfer effect should be checked.
If the transfer is not good, check the roller, printing plate and cardboard and other factors
.

04 Ink foaming

Phenomenon: Too many water-based ink bubbles will cause white spots, sand holes, water marks and other phenomena on the surface of the printed product
.
Mainly due to insufficient ink circulation, too much water, too much pump circulation, and too little air leakage in the tube
.

Solution: Appropriately add defoamer (0.
2% or mix both internal and external plasticizers and defoamers) to reduce the circulating volume of the pump and replenish new ink, so that it does not dilute the inspection tube excessively and prevent air leakage
.

05 Poor drying

Phenomenon: The graphics and texts of the printed matter are poorly dried, too fast or too slow
.
The viscosity of the main water-based ink is too high, the edge of the edge is enlarged, the drying of the water-based ink is poor, and the paper absorption is poor
.

Solution: first check whether the drying of the ink is suitable, it is best to use fast-drying ink; check whether the viscosity of the ink is too high, if the viscosity is too high, further dilute the ink; check the absorption performance of the cardboard, if the absorption performance is too high If it is poor, it is necessary to replace the cardboard with good absorption; check whether the edge of the imprint is enlarged.
If the expansion is caused by improper printing pressure, the printing plate pressure should be adjusted or a new printing plate should be replaced
.