Application of water-based gravure printing ink

The future development of water-based gravure inks should develop toward the full water-based and high-speed printing of inks.

With the gradual enhancement of people’s awareness of environmental protection, the voice of “loving the earth, protecting the ecological environment, and safeguarding the physical and mental health of human beings” is increasing. However, the rapid development of high-speed, automated, and linked processing technologies in the printing industry has resulted in the emission of a large amount of organic volatiles into the atmosphere each year. These industrial compounds pose a serious threat to human security and economic sustainability. Nowadays people are taking Measures to control pollution and improve the environment.

The significance of water-based gravure ink application

One of the development directions of printing inks in the 21st century is environmentally friendly inks, ie, low-pollution or non-polluting inks, including high solids and solventless inks, water-based inks, powder inks, and radiation (UV/EB) inks. Among them, water-based ink is the most important thing. In recent years, the packaging industry in China has caused serious environmental pollution. The current serious problem is that most of the printing inks used are traditional solvent-based products. A large amount of volatile organic solvents (especially benzene and ketone solvents) and many harmful substances left in the printed matter have been given during the printing process. The environment and people's physical and mental health have brought great harm. Therefore, printers and ink manufacturers are actively seeking new materials and new technologies to replace traditional solvent-based inks, which will promote the research, production and application of environment-friendly water-based gravure inks. The future development of water-based gravure inks should develop toward the full water-based and high-speed printing of inks.

Water-based gravure ink features and difficulties

The water-based ink that uses water as the main solvent has the biggest feature of being environmentally friendly, has no impact on human health, is not easy to burn, and has good safety. It is an environmentally friendly ink. However, with water as the main solvent, formula design for aqueous inks, ink performance, printing process and print quality have brought a series of new problems, which makes the application of water-based inks subject to certain restrictions. The difficulties are mainly reflected in the following five points:

1. Due to the higher surface tension of water, this causes difficulty in the wetting of the substrate and the pigment, and the levelness of the print is affected.
2. Compared with organic solvents, the evaporation heat of water is high and the drying is slow. This requires the adoption of corresponding measures to promote the rapid evaporation of water.
3. Pigment fillers have poorer dispersion stability in aqueous inks than solvent inks and tend to aggregate and precipitate.
4. The conductivity of water is high and it is easy to corrode metal.
5. Formulation of water-based ink is more complex than solvent-based ink, and there are many additives, which often cause the performance of the two sides to be out of balance.

Characteristics and advantages and disadvantages of cigarette packs

The biggest characteristic of water-based gravure inks used on cigarette packs is that they are stable in water before printing and insoluble in water after printing. The advantages and disadvantages of water-based inks and solvent-based inks are shown in the following table:

The main technical problems

The main problem that currently exists is hierarchical printing. Due to the insensitivity of water to electrostatic effects, the use of water-based inks will cause different degrees of lost dots for demanding printed products with layers, by adjusting the printing viscosity of the ink, the ratio of diluted solvents, and the softness of the embossing rollers. Hard and other factors can be alleviated or eliminated, but with the extension of printing time, there will be some repeated.

Reprinted from: "Global Box Industry"