Flexo printing common faults and solutions

In recent years, flexographic printing has developed rapidly in China, especially in product packaging, and more and more flexographic printing methods have been adopted. However, in the actual production process, due to the influence of printing materials, ink properties, printing machinery, work environment and other factors, some printing failures often occur, affecting the smooth progress of production and the quality of the final printed matter. Fault paste version reasons: 1, printing plate relief too shallow; 2, printing pressure is too large; 3, too much ink supply; 4, ink viscosity is too high; 5, ink drying too fast. Solution: 1, re-plate, and appropriately reduce the back exposure time, increase the depth of the printing plate relief; 2, appropriate to reduce the printing pressure; 3, appropriate to reduce the amount of ink; 4, reduce the viscosity of the ink; 5, reduce the hot air drying The intensity of the vehicle is appropriately slowed down, or an appropriate amount of slow drying agent is added. The second cause of the problem is: 1. Insufficient ink drying; 2. Insufficient ink viscosity; 3. Too much rewinding tension; Solution: 1. Increase the drying temperature, or add an appropriate amount of solvent with high evaporation rate; 2. Reduce the ink The viscosity; 3, reduce rewind tension. Failure of the three sets of printing is not allowed due to reasons: 1, improper tension; 2, improper arrangement of printing color group; 3, mechanical vibration or mechanical deviation; 4, printing materials are not even; 5, improper temperature and humidity in the printing workshop, drying box temperature is too high , Paper, especially plastic film shrinks severely. Solution: 1, adjust the unwinding and winding tension; 2, re-adjust the printing color sequence, the strict registration of the color arrangement in the adjacent color group next to the printing, in order to prevent deviations, if necessary, can be properly Add one or two layers of transparent tape under the double-sided adhesive; 3, check the machine, and adjust the corresponding machine parts; 4, adjust the tension, or replace the printing materials; 5, reduce the drying temperature, and try to keep the temperature constant in the workshop Wet, if conditional, install the air conditioner in the workshop; fault four stacked color effect is not good reasons: 1, the former color ink is not dry enough; 2, the viscosity of the latter color ink is too high. Solution: 1, adding a suitable amount of volatile solvents to improve the drying speed of the previous color ink; 2, reducing the viscosity of the latter color ink. Failure of the five ink foaming reasons: printing speed is too fast, and there is no defoamer or defoamer dosage insufficient. Solution: Add an appropriate amount of defoamer, or appropriately reduce the printing speed.