Process requirements for pearlescent ink printing

The printing process has a great influence on the quality of printed products. In order to ensure the printing quality, the printing process should match the performance of the ink. For pearlescent ink, the pigment particle size is relatively large, so attention should be paid when selecting the screen mesh. In addition, other aspects such as printing pressure and printing speed are also different from other fabric printing.

① Selection of the mesh number of the screen: The mesh number of the screen has a great relationship with the aperture of the screen. The higher the mesh number of the screen, the smaller the aperture of the screen. The aperture of the screen is related to the particle size of the ink pigment particles used in the printing of dramas. In order to enable the ink to smoothly pass from the printing plate to the printed piece without blocking the screen, it is generally required that the aperture of the screen should be the size of the pigment. 1.5~2.5 times of the largest particle. However, it should be noted that the mesh size of the screen is not as small as possible. The image printed by the screen with too low mesh is too rough. Therefore, the mesh size of the screen should be selected appropriately. It can be seen from the experiment that the ink prepared by A is suitable for printing with a screen of about 50 mesh/in, and mainly prints some rough prints. The ink prepared by B is suitable for screen printing of about 80 mesh/in, and can print some finer prints.

②Other requirements of the screen printing process: Since the printing is a pearlescent oiler, the requirements for the pearlescent effect of the printed product are very high. In addition to the influencing factors discussed earlier, other process conditions also have a great influence.

The appearance of the pearlescent effect depends to a large extent on the thickness of the ink film. The thickness of the ink film is thick, and only a large amount of pearlescent pigments with large particles can exist in the ink film. At this time, the pearlescent effect is obvious. Therefore, try to ensure a large amount of plastic when printing. In printing, try to use a higher printing pressure, a smaller printing speed and a smaller embossing angle (that is, the angle between the scraper and the screen). The ink film of the printed product is thicker, so that the printed product has a good pearlescent effect. Table 1 shows the relationship between the particle size of pearlescent pigments and the mesh number of the screen, and Table 2 shows the printing effect of inks using different pigments and screens with different mesh numbers.

Table 1 The relationship between the particle size of pearlescent pigments and the number of screens