Flexo Ink Troubleshooting (5)

(B) Analysis of the reasons

1. The printing pressure between the material being printed and the plate is too high. The pressure on the contact side of the screen roller and the plate roller is too large, and the ink is pushed to the edge of the printing plate graphic. The margin of the post-print graphic is extremely thick.

2. The printing plate wears, the edge of the printing plate is easy to wear first after pressing, and the heavy image is obvious after pressing; the paper wrinkles in the printing, causing partial thickness variation, local unevenness and ghosting; the embossing roller has dirt.

3. Plate roller accuracy. Printing plate roller gear wear, bearing clearance, etc., will produce greater vibration when the pressure, resulting in inconsistent circumferential imprinting force, resulting in ghosting after printing.

4. Plate hardness is too high or uneven thickness.

5. Too much ink, high viscosity.

6. Poor ink mixing, uneven pigment distribution.

7. The hardness of the plate is soft and the movement of the force is backwards. The pressure at the deformation site is not enough and there is smear.

8. The ink dries too quickly.

9. The double-sided tape is too thin or too hard or contains bubbles, and the local height increases.

(three) solutions

1. 1 re-print pressure plate, pressure is the amount of compression plate. In order to obtain a good print product, the ink layer is required to be uniform and the imprinting is clear. It is necessary to make the graphic part of the printing plate have sufficient elastic pressure contact with the substrate. Before using a set of plate rollers, be sure to use the "regulator" (caliper gauge) carefully adjusted. Under the condition of ensuring the combined pressure of printing, between the printing plate and the anilox roller (printing plate thickness + double-sided adhesive thickness -0.02mm), between the printing plate and the substrate (printing plate thickness + double-sided adhesive thickness + substrate thickness About 0.01mm), determine the above two pressures.

2 The pressure of the anilox roller and the plate roller is constant (0.02-0.03). The pressure of the plate roller and the printing roller can be adjusted according to the different properties of the substrate. The pressure adjustment can be displayed by the two-sided pressure gauge data.

2. Make a new version and prevent wear; check the cause of wrinkles, adjust the exclusion; clear.

3. Check printing roller, shaft, journal and gear runout.

4. Grinding plates on the back or glue strip adjustment or new version.

5. Reduce the amount of ink, reduce viscosity.

6. Uniform and reasonable.

7. Ask the plate maker.

8. Add slow drying agent.

9. Fully vented using a compressible double-sided tape (sponge).

Nine, poor ink transfer

(I) Performance phenomenon

Insufficient ink is provided on the material to be printed, and the ink transfer is difficult.

(B) Analysis of the reasons

1. Ink dilution too much.

2. Dry ink is present on the plate.

3. The surface of the printed material does not accept the ink properly.

4. Inadequate pressure between the transfer roller plate and insufficient printing pressure.

5. Plate hardness is not enough or uneven.

6. Web roll wear, ink roller aging.

7. The surface of the substrate is uneven.

8. Ink drying is too fast and greater than the print speed.

9. The ink contains foreign matter that is incompatible with the ink.

10. Squeegee pressure is too high.