First, the ink is not well prepared

Assuming that the pigments in the ink are properly formulated, the usual cause of the color change is the added solvent. In a well-controlled workshop, the ink should be ready to be supplied to the press at any time, that is, the printer should not dispense ink.

In many companies, the ink is not adjusted and supplied to the press, but left to the printer to adjust and add and mix the ink according to their own feelings. As a result, the pigment balance in the ink is broken. For water-based common inks or UV inks, the water in the ink acts in the same way as the solvent in the solvent ink. The addition of water causes the dried ink film to be thinned and affects the color of the ink, thereby reducing the density of the color. .

The reasons for such problems can be further traced. In the ink warehouse, the ink-filling worker does not use the weighing device, and only relies on his own judgment to add an appropriate amount of solvent, or the mixing is not suitable at the beginning, or the amount of ink changed during printing, so that the mixed ink will Produce different colors. This situation becomes worse when the job is printed again later, and unless there is enough ink ratio recording, it is almost impossible to reproduce a color.

Second, the screen selection is not suitable

Any screen printer who finds that the mesh size is only a variable of the screen structure will only affect the deposition of the printing ink, then he will have trouble. The wire diameter of the wire mesh and the way of weaving, that is, plain or twill, have a great influence on the thickness of the printed ink film. The screen supplier will provide detailed technical information on the screen, the most important theoretical ink volume, which indicates the amount of ink passing through the screen mesh under certain printing conditions, generally expressed in cm3/m2.