Water-based ink is a combination of four different chemical raw materials. They are:

· Colors - It conveys the visual sense so that we can see the colors.

· Resin - it will transfer color to the surface of the printed body.

· Additives - It is a combination of some raw materials to correct the performance of ink.

• Solvent - It reduces viscosity to allow the ink to be transferred to the printed body more easily and then dried.

Of course, the water-based ink solvent must be water, but some suppliers still mix some flammable solvents, also known as water-based inks.

For now, the main function of ink is to present a message or display a selling point. It is also often a perfect picture, so the most important part of printing ink is toner.

The colorant is one of a dye or a pigment. The dye is a general color agent and can be found in foods with colorants and ballpoint pen inks. Although the printing effect is not good and is easy to fade, some paper and board printing are still used due to low prices.

Today's high-quality inks are chemically synthesized using pigments, with the exception of the famous carbon blacks and a large number of dioxides. The fact is that the appearance of the pigment and its properties come from the resin that carries it. The formula of more than 100 kinds of pigments made of ink can cover the spectrum of all colors, but in normal use, typical ink formulations are limited to about 50 kinds.

Some of the world's pigment manufacturers include BASF in Germany, as well as some very small factories. Pigments are manufactured in batches, but the color of each factory is slightly different. The common four-color inks: blue, magenta, yellow, and black, each have a little bit of difference, and there is no real standard. In particular, the colors that the Oriental and Western markets place their emphasis on are different. Take the magenta ink as an example. The east prefers blue ones and the west prefers yellow ones.

Pigments are expensive components in inks and increase costs due to the requirement for higher resistance and higher color strength.

The choice of printed material will also affect the choice of pigments. For example, there is a special case. We are asked to make a blue ink that will be printed on white cardboard. However, the proof is made of yellow kraft paperboard.

Another part of the ink formulation is a resin or carrier transfer system. The main function of the resin here is to transfer the pigment from the printing process to the printed body. In the first step of these processes, the resin is dissolved in a solvent and passes through the printing plate to the object to be printed. After the solvent is absorbed or evaporated and dried, the resin is left to bear and maintain the color. We have a lot of resins to choose from, but it's not possible to use just one resin. Maybe we will consider different resins for the printing requirements, such as: high temperature resistance, acid resistance, high gloss...

Typical resins for aqueous inks are:

· Prevents water diffusion of particulate resin.

· Resin that does not dissolve in water.

· Resin dissolved in alkaline water.

The third element of the ink composition is “water”. Its main function is to make the ink more fluid, so that the ink can be carried from the engraved ink groove of the pattern roller to the printed object, and the resin and the pigment are brought to the printed material. In the body, more water must be removed, which is more difficult on the non-absorbent printed material, so the removal rate and drying speed are very important in the printing process.

The water in the ink is limited to organic solvents because it affects the drying speed of the water and reduces the dissolving power. The water in the ink is not sluggishly added. The pH, hardness, and softness of the water all affect the dryness. We soon talked about the pH of the water.

Additives have the least amount of water-based inks, but their addition is the best way to visualize or correct ink performance. There are many kinds of additives, we must choose its function, and it can be completely combined with ink components. Additives include surface smootheners, defoamers, levelers, synthetic resins, and the like.

Here we talk about the use of certain raw materials, such as heavy metals, chemical solvents, synthetic resins, etc. These will cause environmental problems. I recall that some suppliers mentioned earlier did not restrict the use of such materials according to standards. There are still many problems in this area in Asia. Although the government's laws and regulations are not strictly regulated, you must consider exporting.

A typical printing ink composition would be:

·Solvent 70%

·Color 10%

·Additive 5%

·Resin 15%

Of course, this is only a rough figure, and the final decision has to be made based on the requirements of ink and print quality. For today's high-quality flexographic printing, the pigment content can be added to 17%, which means that we can consider the need to adjust the proportion of ingredients. The most important thing for a printer is to achieve satisfactory quality at an acceptable cost; it also has to take into account both environmental protection and health issues.

The basic concept of ink is already there, but I would like to state that this is the simplest version. We return to the viscosity problem. Each of the factors we talked about above will affect the viscosity.

Often ink companies ask you what viscosity you need, or recommend what viscosity you use. However, the ink viscosity is very important, whether it is a job for another job, or the press for another press, or other situations may have different viscosities. It depends on several aspects, different printing models, with ink roller, scraper or different pattern wheel and mesh thickness.

Viscosity is easily measured in the cup, but attention must be paid to changes in temperature and the cleaning and protection of the measuring cup.

In terms of drying, evaporation of water is a very important factor, especially in non-absorbing materials, where an energy can be used to evaporate the solvent. Water's humidity is the coefficient of surface tension of the water and a coefficient between the printed objects. The water will naturally form a minimum surface area, adjacent to the boundary of the printed body so that it cannot be wetted. The drying of the water-based ink absorbs both the imprinted body and the imprinted body. It is clear that the imprinted body, such as a plastic film, does not absorb water unless it is absorbed. Even if the absorbed imprint can only hold a considerable amount of water, if the water and the resin are not completely absorbed and separated when they are dry, that is, the water volume of the imprinted body is saturated, the watermark ink that no longer absorbs the ink will not be dried. At this time, there will be a color shift if worn.

pH is a very important factor in aqueous inks, and lack of control or incorrect pH can cause many problems. PH value is a method to measure the acidity and alkalinity of the solvent. PH value ranges from 0-14, but you don't have to stare at numbers 6, 7 or 8 or 9 too much, because there are people who use 100, 800, or 900. What is really paying attention? That is, PH value will affect the viscosity of aqueous ink. In the typical water-based printing ink, it can be seen from the graph that the general PH value range should be between 8 and 9.

Several simple steps to control the ink:

· Stir thoroughly before use.

• Detect the ink viscosity of the upper printing press.

Adjust viscosity and reconfirm viscosity and pH.