Environmental friendly water-based ink is best added with dispersant and wetting agent in the production of color paste. Generally, the fineness of water-based inks should be between 101 μ m and 25 μ m, too fine or too large, which will affect the fluidity and rheology of ink.
The viscosity of environmental friendly water-based ink refers to the consistency of water-based ink, which is an indicator of ink flow. The viscosity is too high, resulting in poor fluidity and slow drying; low viscosity water-based ink has good fluidity, fast drying, thin ink layer and less ink consumption. If the viscosity of water-based ink is low, the color powder content is required to be high; otherwise, the color powder content is low.
Because viscosity directly affects ink transfer and printing quality, it is very important to control viscosity of environmental friendly water-based ink. In the printing process, low viscosity will cause light color, high viscosity will cause dirty plate, paste plate and other phenomena, so when it is difficult to control, please add transfer agent, which can improve the transfer effect, increase the bright color and stereo sense.
Environmental friendly water-based ink is different from solvent based ink, the biggest feature is the dissolving carrier used. The dissolving carrier of solvent based ink is organic solvent, such as toluene, ethyl acetate, ethanol, etc., while the dissolving carrier of water-based ink is water and a small amount of alcohol (about 3% - 5%). Because water is used as dissolving carrier, environmental friendly water-based ink has obvious environmental protection and safety characteristics: safe, non-toxic, harmless, non flammable and non explosive, almost no volatile organic gas.