Why multicolor overprinting in screen printing to be unclear?
Analysis of the cause: When multi-color overprinting was performed on the screen printing machine, it was found that the position of several colors of the image was relatively misplaced on the printed product. This is a fault phenomenon in which the overprinting is inaccurate in the screen printing. The tension used in the screen frame is inconsistent, and the mesh distance is adjusted too large when the machine is adjusted, which causes the ink scraping pressure of the squeegee to be different during printing, resulting in a change in the position of the printed images of each color, resulting in an inaccurate overprinting phenomenon.
Trouble-shooting: Clean the screen, and then re-stretch the net after drying. It is required that the tension of the stretcher of each screen should be consistent in a set of screens, and the tension difference should not exceed 1N/cm. At the same time, we must pay attention to re-adjust the mesh distance to 2~5mm. Then start printing, the printed product meets the registration requirements and is qualified.
It should be pointed out that in screen printing, it may also be that the screen printing frame deformation causes the position of the graphic of each color plate to be inconsistent, or because the mesh and the frame are not firmly bonded, part of the opening occurs, causing the image position to occur. Change; it is also possible that the screen version has a gap error in the positioner on the printing plate or the positioner is not fixed firmly, so that the positioning of each color plate does not match the standard during printing: or the printing material is unstable, and the printing will not cause overprinting. Quasi-fault phenomenon. Therefore, when the machine is not inaccurate, if it is difficult to find the main cause of the malfunction, it should be checked item by item according to the above analysis until the cause is found.