Talking about the characteristics of water-based gravure printing ink

Water-based gravure is a new type of ink with low toxicity or practically non-toxic, non-irritating, non-flammable, non-explosive, and is most suitable for gravure printing of food packaging. However, the general water type gravure ink has the disadvantages of no light, dust falling, and low density. If you use the printing ink printing effect may reach: clear text, complete network, strong color, distinctly structured prints.

In general, water-based gravure ink has the following characteristics:

1 It is non-irritating, non-flammable and explosive. It meets the requirements of environmental protection and can protect the health of workers to a certain extent and contribute to safe production.

2 The printing effect is relatively good, the text is clear, the dot is complete, and the color is strong.

3 not impermeable, non-proliferation, indiscriminate rubbing, light gray.

4 can meet the requirements of rapid printing, to create conditions for the development of gravure printing technology, on behalf of the development direction of gravure ink.

The composition of the water-based gravure ink is: water-soluble resins, pigments, various additives and water. In the process of formula design, we must explore, test and appraise from the formula, process, physical and chemical properties and indicators.

In the selection of pigments, it has been proved by experiments that salt-based lake pigments and soluble azo pigments are not suitable because they contain sulfonic acid groups, carboxyl groups, and the like that react with amines and other ions in an alkaline medium. The pigments will undergo reactive coagulation and other pigments can be used. If the filter cake with active agent can be made, the efficiency can be improved.

In order to prevent foaming during use, defoamers such as tributyl phosphate, dibutyl phosphate, and silicone oil may be added to the formulation in an amount of about 0.5%. In order to prevent coalescence and mold during storage and transport, stabilizers may be used. Dispersants, such as light silica gel, sodium hexametaphosphate, and the like. Antisepsis can be used benzoyl, sodium benzoyl sodium, etc., the amount of 0.5% to 1.1%.

According to experience, the design of water-based gravure inks in the viscosity, dryness, preferably controlled within the following range:

Ink viscosity (50 ~ 105) × 10-3pa · s (25 °C, rotational viscometer)

Initial dryness 10～20mm/15s (25°C)

Not more than 160s/100μn (25°C)

The dry form of water-based inks cannot be ignored. Since the latent heat of evaporation of water is large, the drying speed is slowed down, and at the same time, because the amine salt is decomposed due to heat instability, it is mainly volatile and dry, and it is reactively solidified and dried. Once the ink film is dried, it is no longer soluble. Water.

Since the ink is of water-based type, the printing unit is required to have corresponding cooperation in respect of different papers in printing production, dye drying equipment, and operation and the like.

In water-based gravure ink production and production technologies, some properties such as ink film properties (gloss and resistance), printing and storage stability (viscosity stability, mildew resistance), drying speed (material deformation, printability) are still required. The focus of the solution needs further study and resolution.