Color management example of the hottest digital pr

2022-07-29
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An example of color management of digital printing press

ink absorption can be considered from the perspective of pore size. After the ink is filled into the pores, the capillary in the paper absorbs the binder in the ink. If the pores between the paper fibers are very small and the capillaries of the fibers are damaged, the ink absorption performance will be very poor; If the pores between the paper fibers are too large and the ink absorption is too strong, when the viscosity of the printing ink is low, the capillary not only absorbs the binder, but also absorbs the pigment, which will cause the ink to penetrate into the back of the paper, and affect the thickness of the ink layer after drying, so that the imprint cannot show the proper color saturation on the paper surface, affecting the quality of the print

the amount of penetration in the pressure penetration stage and the free penetration stage is closely related to the absorption performance of the paper, especially the free penetration. Therefore, the stronger the ink absorption of the paper, the faster the paper absorbs the ink binder, and the faster the drying speed of the ink. The ink absorption of paper is closely related to the quality of printed matter. Many printing failures are caused by the mismatch between the ink absorption of paper and the printing conditions

1. the ink absorption of the paper is too strong

(1) the imprint is Matt and powdered. In printing, the paper mainly absorbs the binder in the ink. If the paper has too strong absorption capacity for the ink, the binder is excessively absorbed into the paper layer or coating, resulting in a lack of binder in the ink layer on the paper, making the pigment particles suspended on the paper. After the conjunctiva is dry, the imprint color of the printed matter will age or lose luster, and even some imprints will be rubbed, The pigment will peel off in granular form, resulting in pulverization. When the chalking is serious, the ink layer of the previous color will be peeled off from the paper during the overprint process

the solutions are as follows

① replace the appropriate paper

② use tackifier to increase the viscosity of the ink, or add inking oil with high resin content to the ink

③ adjust the humidity of the paper

(2) through printing

the viscosity of the ink is small. When the printing pressure is too large, the paper has too strong absorption of the ink. Therefore, the precision binder penetrates into the internal pores of the paper, replacing part of the air in the pores of the paper, resulting in the reduction of the scattering interface between air fiber, air filler and air paint, reducing the light scattering ability of the paper and increasing the transparency, which may lead to the occurrence of through printing for important purposes

the solutions are as follows

① replace the appropriate paper

② reduce the printing pressure

③ improve the ink viscosity

(3) the density of the ink layer decreases and the hue changes

when printing on a paper with large pores, some pigments and binders will penetrate into the paper together (the pores of the paper fibers are larger than the pigment particles). Excessive infiltration of binders will dry the imprint, reduce the tinting power of the ink, reduce the saturation of the ink layer, and significantly reduce the color concentration of the printed matter. At the same time, the obvious decrease of the color concentration of the printed matter will also change the hue of the printed matter and affect the correct reproduction of the gray balance

the solution is as follows:

① replace the appropriate paper

② carry out ash balance data test again for this kind of paper

2. the ink absorption of the paper is too weak

the ink absorption of the paper is too weak, and the speed of ink absorption is too slow. Although a colorful ink layer can be obtained during the printing process, it affects the penetration, fixation and oxidation polymerization of the ink, resulting in a reduction in the speed of ink fixation. After the ink is transferred to the paper, it cannot be quickly absorbed by the paper. In this way, the wet ink will be transferred to the back of the other paper covered, resulting in dirt, Adhesion may also occur in severe cases

1. User requirements:

the solution is as follows:

① replace the appropriate paper

② properly increase the printing pressure

③ reduce the ink viscosity

④ reduce the printing speed. (end)

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