Several drying methods and technologies for future new inks

1. Thermal polymerization drying

After the ink is printed, it must be heated to undergo polycondensation and cure. Heat curing ink is a mixture of resin and curing agent, and then printed and heated to make the resin react to form an ink film. This kind of ink is called heat polymerization ink. The advantages are one-liquid type, solvent-free, stable viscosity before heating, good fastness and resistance to printing on the printed product, and the disadvantage of high energy consumption. The curing speed of this ink depends on the content of the catalyst and the heating temperature. When no catalyst is added, the ink needs to be cured at a temperature higher than 150 degrees. After the catalyst is added, it can be cured at an intermediate temperature. However, the catalyst content is too large to facilitate the preservation of the ink. The physical properties of this ink's hardened ink film are very good, mainly for metal and plastic printing.

2. Gelatinization drying

Gelatinized dry inks use plastisol inks. The ink disperses the polyvinyl chloride together with the pigment in the plasticizer. After printing, the polyvinyl chloride particles expand under the action of the plasticizer and form a plasticized polyvinyl chloride film. Thus, the polyvinyl chloride film is realized. dry. Plastic silicone inks can be used as foaming inks, printing and dyeing inks, and fiber inks.

3. Filter drying

The combination of osmotic drying and gel drying for drying is called filtration drying. When the coating is printed with a fast-drying ink, the low-viscosity petroleum solvent in the binder is quickly absorbed into the coating by capillary action of the coating. The resin components that have been expanded into a gel form contain the pigment particles therein, remain on the paper, and the ink cures.

4. Wet and dry

Wet ink is used to print on the paper and steam is blown in. Moisture in the air or water in the paper is absorbed by the ink. The resin dissolved in alcohol at the same time precipitated and precipitated. The ink begins to dry, and the water eventually evaporates out of the paper due to volatilization. When using this kind of ink, special attention should be paid to picking the proper ink roller.

5. Precipitation drying

The binder of the precipitation-drying ink is prepared by dissolving a high acid value resin in an alcohol, and the resin to be used is capable of being limitedly compatible with water, but precipitates immediately beyond a limited amount, typically represented by rosin-modified maleic acid. Resin. Commonly used alcohol solvents such as ethylene glycol. The drying of the ink is performed with water as a precipitant, so the solvent used for the ink must be able to mix with water in any ratio.

6. Condensation drying

Wax inks are very important cold-set inks. For example, a carbon-carbon ink is heated and printed, is a solid at normal temperature, and when printed on a voucher printing machine, it is fluidized by heating and melting, and can be printed with a relief plate or a lithographic plate, and is condensed and dried through a cooling roller.

7. Microwave drying

Microwave drying is also a means of heating the ink to dry it. Under the action of the microwave electromagnetic field, the heated media molecules become polarized molecules with positive and negative charges. These polarized molecules vibrate with the change of the electromagnetic field, and the temperature also increases.

8. Reaction curing type

This ink is different from the previous two-component reactive curable inks. When the ink comes in contact with paper, certain components of the ink react with certain components of the paper and dry and solidify. This reaction exists on the coating layer on the surface of the ink and paper, so that the ink cures rapidly and there is no problem of volatile pollution. However, inks and papers that can react with each other must be selected for printing.