Author: Site Editor Publish Time: 07-20-2022 Origin: Site
Whether it is a single-color offset press, two-color offset press or multi-color offset press, the problem of downtime due to rubber blanket failure is often encountered, here only four-color printing process encountered in the analysis of a case of rubber blanket failure to discuss, I hope to encounter the same situation of peer inspiration.
After the replacement with a new rubber blanket printing 100,000 printed offset paper live, change the printing of coated paper, the official printing after the completion of preparatory work, the first few hundred printed normally, after the first color group of prints are false, especially the phenomenon of field graphics white. Cleaning the rubber blanket after the test printing, and this situation.
Initially judged to be too small, increase the amount of ink still does not help, inferring that the ink is viscous, the paper surface strength caused by low paper plucking, after checking this possibility was ruled out.
So focus on the ink transfer from the consideration, visual inspection of the printed graphics part of the ink layer full, but the amount of ink on the rubber blanket is clearly insufficient, so the first few hundred normal when printing, thus ruling out the factor of insufficient printing pressure.
With a cloth dipped in water lightly wipe the surface, found that the water film is more evenly coated on it, thus judging that the rubber blanket rubber layer of sand in the mesh has been pressed into the paper powder, glue and other hydrophilic substances, so that its lipophilicity is reduced, the ink can not be well adsorbed and transferred, resulting in printing graphics white and false.
Because this piece of rubber cloth is newly replaced, there is no aging problem, how to remove the surface of the rubber layer of sand in the remaining hydrophilic substances, determine whether this piece of rubber cloth can be used.
If you use the reducer for cleaning, the effect is not ideal. Polishing with talcum powder, residual talc will increase the wear and tear of the printing plate, this method is also not desirable.
Finally, we tried a new method, and found good results, the specific practices are as follows.
(1) wash the surface of the rubber blanket residual ink, with a cloth dipped in gasoline coated on the surface.
(2) lightly scraped with a single blade, scraping off the gasoline rubber blanket surface whitish, with a little powder.
(3) with a cloth dipped in water coated on the surface of the eraser cloth, and then scrape lightly with a blade, at this time scraping down the water droplets are white.
(4) wipe the rubber blanket after the opening of the print, the print sheet is full, thick ink layer, clear network, troubleshooting.
It is worth mentioning that, when scraping the surface of the rubber blanket with a razor blade, you can not use too much force, or damage to the surface of the rubber layer is not worth the loss.