Simple measures to improve the overprinting rate of water-based ink.

   Printing houses often encounter the problem of low overlap rate. The color of

the post-print cannot completely cover the previous color, and there will be pitting,

which will seriously affect the printing effect. How to improve the overprinting

rate of water-based ink?

   1. Accelerate the drying speed of the first color ink on the substrate, and set

the two inks that need to be stacked in the first color group and the last color

group respectively, which can increase the drying time of the first color ink layer

and facilitate overprinting rate increase. The use of quick-drying ink in the first color

printing can speed up the penetration and fixation of the first color ink. It cannot

be dried too fast, otherwise the ink has dried on the screen roller, which will affect

the transfer of ink. Pay attention to arrange the printing color sequence, try to print

the color with smaller image and text area first, and print the color with larger image

and text area later. The graphic area of the first color printing is small, and it dries faster,

which is beneficial to the overprinting of the ink; because the graphic area is small,

it can reduce the chance of the ink layer being dirty by the last few color groups of

the cardboard during the transfer process. Under the premise that the color saturation

meets the requirements, reduce the thickness of the ink layer of the first color.

   2. Adjust the relationship between the fluidity and viscosity of the two inks.

For brightly colored printing, it is best to use a stabilizer to lighten the color of the ink,

which is conducive to the drying of the ink. At the same time, the auxiliary agent can

improve the gloss of the ink layer. Diluted with water, it cannot be dried instantly,

but must have a drying time, which will reduce the edge compressive strength and

compressive strength of the cardboard. In addition, adjust the relationship between

the viscosity of the first color and the post-printing color. For multi-color printing,

properly reduce the viscosity of the first color water-based ink, and properly increase

the viscosity of the second color ink to increase the overprinting rate.