The problem of dirt in packaging and decoration offset printing products can be analyzed from two aspects: 1. The plate itself is dirty (including printing), Generation And Elimination Of Dirt In Packaging Offset Printing

    2. The printing plate itself is not dirty, but caused in the printing process.Generation And Elimination Of Dirt In Packaging Offset Printing

Printing plate

1. Cause: poor version base or regenerated version; Treatment: replace the printing plate.Generation And Elimination Of Dirt In Packaging Offset Printing

2. Cause: insufficient exposure of printing plate and aging of light source; Treatment: properly adjust the exposure time or replace the light source.Generation And Elimination Of Dirt In Packaging Offset Printing

3. Cause: the transparency of Yangtu film is poor; Treatment:

      remake the positive film.Generation And Elimination Of Dirt In Packaging Offset Printing

4 reason: the developer concentration is too low and the development is not complete; Treatment: adjust the developer concentration to the standard concentration. Generation And Elimination Of Dirt In Packaging Offset Printing

    Pay attention to adding new solution at any time during the development process, and replace it after a certain period of use.Generation And Elimination Of Dirt In Packaging Offset Printing

5. Cause: the blank part of the printing plate is oxidized; Treatment: printing plate coated with protective glue.Generation And Elimination Of Dirt In Packaging Offset Printing

6. Cause: there are dust or dirty spots on the film and plate printing frame glass; Treatment: remove dust or dirty spots with detergent.Generation And Elimination Of Dirt In Packaging Offset Printing

7. Cause: during development, the blister is attached and the developer spray hole is blocked; Treatment: clean the developer spray hole.Generation And Elimination Of Dirt In Packaging Offset Printing

8. Cause: the protective adhesive coated on the printing plate is too thin; Treatment: increase the concentration or thickness of protective glueGeneration And Elimination Of Dirt In Packaging Offset Printing.

9 reason: there is much dust in the printing workshop; Treatment: the printing workshop and personnel shall be kept clean and tidy.Generation And Elimination Of Dirt In Packaging Offset Printing

10. Cause: the edge trace of transparent glue is produced by manual Collage; Treatment: correct the edge trace of transparent glue.Generation And Elimination Of Dirt In Packaging Offset Printing

11 reason: the developer temperature is too low and the flushing speed is too fast; Treatment: adjust the developer temperature and flushing speed.Generation And Elimination Of Dirt In Packaging Offset Printing

12 reason: the protective glue of printing plate is thin and there is sediment, and it is dirty on baking; Treatment: change the thickness of protective glue, shake it evenly, wipe it evenly, and remove the sediment.Generation And Elimination Of Dirt In Packaging Offset Printing

printing

1 reason: the downtime is long, and the printing plate is not rubbed with protective glue; Treatment: apply protective glue.Generation And Elimination Of Dirt In Packaging Offset Printing

2 reason: the blank part of the printing plate is not wet enough; Treatment: appropriately increase the amount of water.Generation And Elimination Of Dirt In Packaging Offset Printing

3. Cause: the ink is too thin, resulting in flying ink; Treatment: add thickener or change new ink.Generation And Elimination Of Dirt In Packaging Offset Printing

4. Cause: ink emulsification; Treatment: control the ink balance.Generation And Elimination Of Dirt In Packaging Offset Printing

5 reason: the pH value of wetting solution is generally 5. ０——６。 ０。Generation And Elimination Of Dirt In Packaging Offset Printing

6. Cause: rubber blanket aging; Treatment: replace with a new blanket.Generation And Elimination Of Dirt In Packaging Offset Printing

7 reason: the pressure between water rollers is too light; Handle and adjust the pressure between water rollers.Generation And Elimination Of Dirt In Packaging Offset Printing

8 reason: the ink viscosity is too low; Treatment: add tackifier.Generation And Elimination Of Dirt In Packaging Offset Printing

9. Causes: low surface strength of paper, excessive paper powder and paper wool, and wear of printing plate; Treatment: reduce ink viscosity, wash blanket or change paper frequently.Generation And Elimination Of Dirt In Packaging Offset Printing

10 reason: the ink roller pressure is too heavy, and the hydrophilic layer of the printing plate is damaged; Treatment: adjust the pressure of the inking roller.Generation And Elimination Of Dirt In Packaging Offset PrintingGeneration And Elimination Of Dirt In Packaging Offset Printing

11 reason: the hands are not clean wheGeneration And Elimination Of Dirt In Packaging Offset Printingn using the printing plate, and there are fingerprints and sweat stains); Handling: keep hands clean during operation.

12 reasons: the amount of ink is too large, the ink layer of printing is too thick, and it is not easy to dry; Treatment: reduce the amount of ink and make the ink layer reach the standard density value.Generation And Elimination Of Dirt In Packaging Offset Printing

13. Reason: poor dryness of ink itself; Treatment: add desiccant appropriately.Generation And Elimination Of Dirt In Packaging Offset Printing

14. Cause: the printed matter accumulation is too high and the pressure is too heavy; Treatment: reduce the stacking height.

15 reason: the paper transfer drum or embossing drum is dirty; Treatment: wipe the dirt on the paper transfer drum or imprint drum.

16 reason: there are pieces of paper in the machine, and the printed matter is encountered during printing; Handling: remove the shredded paper in the machine.

17. Cause: the semi-finished products are not dry, moving and rubbing; Treatment: move the semi-finished product after it is completely dry.

18. Cause: dirty during paper transfer; Treatment:Generation And Elimination Of Dirt In Packaging Offset Printing

     stick dirty paper or sponge strips.Generation And Elimination Of Dirt In Packaging Offset Printing

     Finally, the generation of dirt has two aspects. One is plate making, which is called basic dirt. Another reason is printing, which is called groundless dirt. Generation And Elimination Of Dirt In Packaging Offset Printing

    These two reasons are different, and the treatment methods are also different. Generation And Elimination Of Dirt In Packaging Offset Printing

      Therefore, when analyzing dirt, the remedy should be tailored according to the actual situation. Generation And Elimination Of Dirt In Packaging Offset Printing

     At the same time, we should constantly sum up experience to greatly improve the quality of packaging and decoration offset printing products.Generation And Elimination Of Dirt In Packaging Offset Printing