Selecting Pigments For Inks

Selection of commonly used ink pigments

Pigment blue 29 manufacturer said, the emergence and rapid development of ink has promoted the development of pigment industry, especially organic pigments. China’s pigment industry has a very broad development prospect, and the organic pigments used in the ink and coating industry account for a large proportion of the world’s total output.

Currently widely used ink varieties are: offset printing ink, gravure printing ink, UV light-curing ink, flexo printing ink, screen ink and special inks, such as inkjet printing ink and so on. The following is a brief introduction to the common ink of several major varieties:

Offset Printing Ink
Offset printing ink is currently used than a very large proportion of the choice of pigments used to consider the following points:

● System solvent, its properties: transparent, colorless liquid, mainly mineral oil and vegetable oil.

● In the printing process, the ink should be in contact with the feed rollers, so the water resistance is good.

● The ink layer is thin when printing, so the concentration should be high.

● Good transparency, especially yellow pigment.

Solvent-based Gravure Ink
Solvent gravure printing ink in the solvent is mainly organic solvents, such as benzene, alcohols, esters, ketones, etc., different system solvents on the choice of pigment and have different requirements, in general, to consider the following points:

● The viscosity of gravure printing ink itself is relatively low, which requires the pigment to have good dispersion, and to have excellent mobility, good storage stability and no changeability.

● Solvent-based gravure ink is mainly volatile drying, so it has good solvent release when drying in the system.

● Solvent resistance should be good, in the solvent will not occur in the phenomenon of color change, color fading.

Ultraviolet Light Light-curing Ink (UV Ink)
UV ink in recent years, in the world is widely used, it is mainly offset printing, flexographic printing and screen printing these three forms. Its drying method determines the choice of pigment, and the production process mainly considers the following factors:

● The pigment can not change color under ultraviolet light.

● In order to avoid affecting the curing speed of the ink, the pigment with small absorption rate of ultraviolet spectrum should be used.

Water-based Ink
Water-based ink is mainly used in flexographic printing, gravure printing two forms, water-based ink generally contains alcohol solvents, so the use of pigments to be alcohol-resistant. From the point of view of sustainable development, water-based ink and UV ink are extremely low VOC, environmental protection, is the future direction of the development of ink, the development of organic pigments should also be developed in this direction of environmental protection.