Precautions for printing with pearlescent ink in silk screen printing

At present, the competition in the cigarette printing industry is very fierce, and the requirements of packaging for cigarette factories are getting higher and higher. If the cigarette printing factory wants to be in an invincible position, it must continuously introduce new products, and if the pearl inks are properly used, they can There are many special effects.

For the choice of printing method, the product must first be analyzed. Each product has different requirements for surface effects. Some require pearlescent pigment particles to be coarse (the pearlescent effect is obvious), and some require pearlescent pigment particles to be fine (the pearlescent effect is weak). For pearlescent inks with relatively coarse particles, it is better to use the screen printing method. On the contrary, gravure is used. Because the pearlescent pigment particles suitable for screen printing are relatively large and the edges are rough, when the light hits the surface, the reflected light is more, and the color is strengthened, brighter, and produces a "shiny" effect, such as Jiangxi. The “Lushan” cigarette label of Nanchang Cigarette Factory.

For some special pearlescent pigments, when the light hits the surface, the interference color can be seen in the direction of the reflection angle, and in the direction of the scattering angle, the complementary color of the interference color can still be seen because the light passes through the thin layer. For example, printing black on pearlescent inks, due to the refractive effect of pearlescent pigments, the angle of reflected light is not the same, the effect is not the same, and the black on the senses becomes dark green. The selected pearlescent inks are different, and the effect is different. For example, the brown color will turn dark red.

First, the substrate "bursts". This problem generally occurs when the cigarette label is printed with pearls. If pearlescent ink is used on the soft bag, it is necessary to use a relatively fine pearlescent pigment and use a gravure method. However, since the substrate of the soft bag is relatively thin, the gravure pressure is large, and the bursting problem is relatively difficult. control.

The second is paper deformation. When the infrared drying is used or the pearlescent printing product is naturally dried, the paper of the cigarette soft pack is easily deformed, and the process control is difficult. However, the situation of printing gold and silver cardboard is much better. The paper with larger quantitative content is more suitable for pearl printing. Generally, if the cigarette paper is at 230-250 g/m2, it is very advantageous for pearl printing.

The third is whether the product has an odor. The cigarette label has stricter requirements on the smell of the package. The pearlescent pigment itself has a small odor, but sometimes the pearlescent ink is not well adjusted, resulting in a large odor generated by the product. By improving the ink and printing equipment, this problem can be effectively avoided.

The fourth is the color difference of printed matter. Due to the difference in the particle size of the pearlescent pigments, the problem of chromatic aberration control is difficult during the printing process. When screen printing is used, it is necessary that the fine pearlescent pigment is first transferred to the substrate through the screen, and the coarse particles are caught by the screen. Therefore, as the printing progresses, the large particles of the pigment accumulate. More, the color of the printed matter will be printed more and more light, resulting in chromatic aberration.

Fifth, the amount of ink is relatively large. The coarse particles of pearlescent pigments also lead to a relatively large amount of ink, the particles are too coarse, and the pearlescent pigments will have residues in the ink, which is relatively difficult to separate and will result in waste of ink. When using pearlescent inks, be sure to use them during the shelf life, and be sure to mix them evenly when using them.