The problem
This problem appeared today. A colleague thinks it depends on the machine, but we are not sure. Can you help us understand what to check?
Cause and analysis
The defect could result from a misalignment of the printing cylinders or from an irregular pressure distribution between the printing cylinder and the transfer cylinder, which causes variability in the density and direction of the screening from sheet to sheet.
The defect could be caused by wear or dirt (dried ink, paper residue) on the dampening cylinders or on the ink cylinder, which alters the consistency of dampening or ink distribution and therefore the regularity of the printed screening.
The defect could lie in the design file or in the RIP/digital printing parameters of the plate (if applicable), rather than in the machine mechanics, especially if the screening was generated with an irregular pattern or with inadequate resolution.
Solution proposed by GPX
A possible cause is the progressive misalignment of the pressure cylinders, which produces differential compression of the screening and explains the variability between sheets.
Limitations of this analysis
This analysis is generated with the support of Artificial Intelligence: always verify its correctness and applicability before using it. The reliability level of this analysis is "Medium", not the highest possible.