Printing ink gloss solution (in)

Second, ink properties

1. The leveling property of the ink, in the printing process, the leveling property of the ink is good, then the glossiness is good; the leveling property is poor, the drawing is easy, and the glossiness is poor.

2. The fluidity of the ink, the fluidity of the ink, the enlargement of the print size, the enlargement of the dot, the thin ink layer, the poor glossiness, the small fluidity of the ink, the reduction of permeation, the flattening of the ink film, and the glossiness of the printed product high. However, the ink flow is too small and the ink is not easy to transfer, which is not conducive to printing. Therefore, in order to obtain better gloss, the degree of fluidity of the ink should be controlled, increasing the viscosity or reducing the flow must all consider other printing conditions, otherwise simply emphasizing the gloss of the print will cause other quality problems.

3. The fineness of the ink, the coarse ink particles, the piles and other faults appear in the printing, the printed products are also rough, diffuse reflection occurs, and the gloss is poor. Conversely, gloss is better, and care should be taken when choosing the ink (especially gold ink, silver ink).

4. The viscosity and viscosity of the ink should not be too large or too small. If it is too large, the surface of the blanket and the printed product will be peeled and drawn. If the size of the ink is too small, the size of the print will be enlarged and the ink layer will be thinned, which will affect the glossiness. Greater China Graphic Arts Network

5. The dry form of the ink, the same amount of ink used in different forms of drying, the gloss is not the same, the general oxidation of the conjunctiva drying is higher than the permeability of the drying gloss, because the oxidized conjunctiva dry ink printing surface material more, and infiltration drying The surface of the ink print has less material. When the ink is transferred to the paper, the solvent part of the link material penetrates into the paper at a faster rate. At the same time, the coating and the paper fiber absorb the link material. The more rough the paper, the absorption ability of the link material is also The stronger it is. In the case where the oxidized conjunctiva is not yet dry, the binder is absorbed by the paper fibers. The remaining small amount of binder and pigment particles adhere to the surface of the paper, thus making the product dull.

6. The amount of driers added to the ink. In addition to the drying properties of the ink itself, the amount of driers added to the ink is also a factor that determines the gloss of the imprint. Due to the increase of the driers, the drying speed can be increased accordingly and the penetration time of the ink layer can be reduced. For example, cobalt driers are mainly used to promote oxidized conjunctiva, and it is suitable to use it. It is fast drying, smooth surface conjunctiva, and has the effect of increasing gloss. The disappearance of gloss is often due to excessive drying time. The absorption of ink by the paper and the penetration of the ink into the paper increase, resulting in the separation of the binder and the pigment. Part of the binder in the ink penetrates into the pores of the paper, making the binder in the The proportion of paper on the surface is reduced. If the infiltration phase is completed as soon as possible, the gloss of the dried ink layer can be improved. On the contrary, the surface of the ink film is diffused and matte.

7. Ink transparency, high transparency of the ink to form the ink film color layer, the incident light part of the ink film surface reflection, the other part of the surface of the paper, and then reflected out to form two color filter, this complex reflection mechanism is rich The effect of color, the opaque pigment formed by the color layer ink film, its gloss is only the surface reflection, the gloss effect is certainly not as good as the transparent ink.

8. The gloss of the binder, the main components of the ink are binders and pigments. The gloss of the binder is a major factor in the ability of the ink blot to produce gloss. The early ink binders were made from vegetable oils such as linseed oil, tung oil, and eucalyptus oil. The surface smoothness of the blotted conjunctiva was not high, and only the fatty film surface was observed. Diffuse reflections were formed on the incident light, and the gloss of the blot was comparable. difference. Now the binder of the ink is mainly composed of resin. After the conjunctiva is blotted, the surface smoothness is high, and the diffuse reflection of the incident light is reduced. Therefore, the gloss of the blot is several times higher than that of the grease and ink.

9. The viscosity of the ink on the adsorptive force between the binder and the pigment. The viscosity of the ink is related to the adsorption force between the binder and the pigment. Increasing the viscosity increases the adsorption between the binder and the pigment. Absorption will be reduced accordingly, so that the reduction in the amount of penetration, the better the gloss, so an appropriate increase in the viscosity of the ink can make the gloss of the print increases.

10. The thickness of the ink layer, the total thickness of the ink surface of the ink sheet has a great relationship with the gloss. Generally, the gloss of a single color print rarely occurs, and if it is overprinted, it will have a luster. Therefore, the thickness of each ink layer is correct. Glossiness has an effect. For example, a thicker layer of ink can lay a foundation for improvement of glossiness. When the number of color registrations is large, the paper surface can be filled and glossiness can be improved.

11. The emulsification of ink, the emulsified ink, must begin to dry after the water evaporates, so the drying is delayed, and many small holes are formed on the surface of the ink layer, which reduces the gloss of the print.

(to be continued)