How To Better Use Water-based Ink?

Neutralizer
Ink factories generally use volatile amination reagent neutralizers when manufacturing high-end inks. The resulting amination resin liquid has good stability and has a small smell.

Currently, carton factories use ammonia or organic amines. Ammonia evaporates relatively quickly and we can quickly obtain a water-resistant ink film that we are satisfied with, but as we all know, its stability is poor. Organic amines evaporate slowly and have relatively stable performance, but don't forget that their water resistance after film formation is very poor. We add different types of neutralizers according to the requirements of the carton pattern, and they need to be added according to different needs during the actual printing process.

Solvent
In addition to alkaline resin and pH value, due to the high surface tension of water, the solvents in the water-based binder include co-solvents in addition to water to improve viscosity, drying performance, stability, dispersion and fluidity to obtain satisfactory printing Effect.

The solvent in water-based binders is generally water, and a solvent that is beneficial to the dissolution of the polymer and has a suitable boiling point should be selected.

It must be noted that different co-solvents must be selected for different polymers to obtain the best ink film quality in the best printing state.

Alcohol solvents such as ethanol, n-propanol, butanol, etc. This type of solvent can assist water in increasing its ability to dissolve resin. It improves the dispersion ability of pigments, accelerates penetration when making coated paper, and inhibits the generation of foam.

Ether solvents are mainly used to improve the drying performance of ink, such as ethyl cellosolve.

pigment
Pigments can be divided into organic pigments, metallic pigments and inorganic pigments.

The advantages of inorganic pigments are: good stability, not easy to decompose, strong resistance to light and atmosphere, and long-lasting color retention.

Organic pigments: small particles, strong dyeing power and high brightness.

Metallic pigments: such as zinc oxide, iron black, iron red, etc.

Water-based inks generally use alkaline pigments. The pigment is required to be well dispersed in the ink. Before being added to the ink, the pigments undergo a series of anionic and nonionic surface active treatments to improve the surface tension and polarity of water. The ultimate goal is better dispersion.

Although water-based inks and non-aqueous inks are both called inks, if they are distinguished in detail, the requirements for pigments of these two types of inks are quite different.

Different pigments have different chemical properties, such as density, pH, polarity, particle size and surface properties. Therefore, do not add too many pigment types during the manufacturing process of water-based ink. We must adhere to the principle of simplicity. Resins are generally alkaline. If you choose acidic ones when manufacturing inks, it may cause the resin to acidify. Resin acidification means that the ink will agglomerate and the chemical properties of the ink will also be destroyed. Can we still print good products in this case?

But if the pigment is too alkaline, the resin will saponify. The same ink performance also undergoes qualitative changes.

Pigments include transparent pigments and opaque pigments. A simple comparison is as follows.

Opaque pigment: It has good hiding power, relatively large particles and is easy to disperse.

Transparent pigment: high gloss, high printing strength and not easy to powder. Due to the small size of the pigment particles and its good transparency, it has good resistance to fading.

In high-end four-color dot printing, transparent pigments are used as the main pigment of the ink. But among the inks used in high-end printing, everyone must remember not to put inks containing white ink pigments as the last color. Because among all inks, white ink has the strongest hiding power.

Therefore, everyone must remember the importance of pigments and resins when choosing inks. Especially when printing high-end four-color dot printing, the high requirements for ink are far beyond our usual imagination.