The future development of screen printing inks is promising (2)

The water-based ink binder is composed of an aqueous gum or semi-gel solvent and an emulsion. The acrylates and copolymers are dissolved in water in an exact ratio, and after adding other solvents, a stable binder is obtained. Adding such a binder to pigments and auxiliary materials can produce screen-printed water-based inks. The particles of the composition have such a characteristic that the moisture can be volatilized and released relatively quickly during the formation of the ink layer film, thus forming a dry ink film. The viscosity of the screen printing water-base ink can be adjusted with water during printing, and the used screen can be washed with water. The ink residue remaining on the screen can be removed by a cleaning machine and recycled. However, the use of water-based inks requires that the screen printing plate must have water resistance, so it is necessary to use water-resistant photosensitive adhesive for plate making.

As mentioned previously, the screen printing water based ink contains particles of the composition in the ink, and when the water is volatilized and released relatively quickly, the surface of the ink film can be rapidly dried. Therefore, at 20 °C ~ 22 °C standard room temperature and 5% ~ 60% relative humidity, it is best to use hot air to promote the water to accelerate the volatilization, especially non-absorbing substrates. Soft or rigid polyvinyl chloride and foil coated with adhesive shall be continuous drying devices. The convective air temperature at the inlet shall be maintained at 70°C～80°C, so that the drying temperature of the printed input of the stack can be maintained. Close to 35°C to 40°C. For different materials, the stack drying temperature should be adjusted accordingly to obtain better ink adhesion than solvent inks. In addition, another measure to improve the drying performance of screen-printing water-based inks is to add a small amount of cross-linking agent to improve the anti-diluent, alkali-resistance, and acid-resistance properties of the aqueous system prior to printing.

Second, electron beam curing ink

Electron beam curing ink, like UV ink, is one of the most promising "green" inks in screen printing. Since the electron beam cured ink is not limited by the ink layer thickness, it is safer to operate than the UV light curable ink.

The Chicago household electrical appliance printing company in the United States has used this kind of ink processing to produce membrane switches. The thick-film screen-printed prints are placed in an electron beam radiation drying device, and the ink is fully dried in a few milliseconds under the irradiation of the electron beam. The gloss of the printed product is good, the film is strong in touch, and it is resistant to friction. The effect is very satisfactory. However, the ink and its radiation drying device are very expensive. At present, there are still difficulties in its promotion, but because it can save drying time, ensure product quality, and do not pollute the environment, it has a promising future.

Source: China Ink Technology Network