The rapid drying of the ink film on the paper surface can reduce the amount of the binder penetrating into the pores of the paper, thereby improving the gloss and smoothness of the ink film. The high gloss of the ink film means that the degree of specular reflection on the surface is relatively high, so that in most cases, the human eye can see that the white light reflected by the surface is much less than that of the ink film with low gloss, making the color saturation more high. Therefore, printed products with high gloss look more vivid and full.
Pigment particle size and degree of dispersion
Although the role of ink film capillary is an important factor in forming the gloss of printed matter, the apparent size of pigment particles in the dispersed state is more important, which directly determines the state of ink film capillary. Therefore, the pigment particles are small and well dispersed, which is conducive to the formation of a smooth ink film and is also very beneficial to improving the gloss of printed products.
Binder viscosity and pigment content
According to the principle of interface chemistry, the capillary permeation velocity is inversely related to the liquid viscosity, that is, the permeation velocity decreases with the increase of viscosity.
The capillary network structure formed between ink pigment particles is an important aspect that determines the gloss of printed matter. At the moment of embossing, the ink is pressed into the larger pores of the paper as a whole; after embossing, the binder begins to separate from the ink and penetrates into the smaller pores of the paper. Therefore, the size of the ink film capillary determines the separation amount of the binder. The role of capillary retention of the binder is much greater than that of printing pressure to press the binder into the pores of the paper.
drying time
The rapid drying of the ink film on the paper surface can reduce the amount of the binder penetrating into the pores of the paper, thereby improving the gloss and smoothness of the ink film. The high gloss of the ink film means that the degree of specular reflection on the surface is relatively high, so that in most cases, the human eye can see that the white light reflected by the surface is much less than that of the ink film with low gloss, making the color saturation more high. Therefore, printed products with high gloss look more vivid and full. Most of the printing ink layers of spot color inks are translucent or opaque. When selecting ink formulations, the influence of the light transmittance of the ink layer on spot color printing should also be considered according to the actual situation.
