engleski

Determination of the minimum dot and anilox line screen used for flexography

The relationship of printing plate dot with anilox line screen cell directly affects the quality of flexo print. Reproducing the elements like blends, vignettes or gradients, flexographic printing with conventional screens at high line rulings in the highlight areas still requires a number of workarounds. Depending on the line screen used, the min imum dot size that can be held on the printing plate and on the press is determined. The minimum dot size is more important factor for flexography. The characteristic of flexographic printing plate that does not hold a minimum dot is hard edge at highlights in the print. Depending on th e minimum dot defined, the used anilox line screen is determined. When the dot on the printing plate is smaller thanthe cell on the anilox roll it creates the effect called "dot dipping" and the print is dirty. This paper will demonstrate the way of determining the minimum dot using the conventional AM screening technology and the advanced XM screening technology. O n that basis, various line screen anilox rolls in relationship to various line screen printin g plate dots will be recommended. Understanding the relationship of printing plate dots to anilox cells will help change and get better your flexo printing process. By following the guidelines in this article, you should avoid the problems of tone breaks and posterization in highlights and dirty printing, and save time and money in the process.

flexography; minimum dot; anilox line screen; XM screening; “bump” curve

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