How to Increase the Platemaking Performance of Photosensitive Resin Plates by Flexoprinting (Part One)

In today's fierce competitive environment, businesses are under tremendous pressure and must continuously improve the image quality of digital or traditional photopolymers. Recently, the development of screening technology can push the plate quality of the flexible version to a new stage.

One of the major limitations of flexo printing is that all dots of the highlights on plates or prints do not form well. Since AM screening has such a limitation, when a small dot or thin line is applied to a digital file, there is often a clear boundary between the transition of the ink layer to the blank area. In the past, people accepted it as usual, or had to increase the color of the highlight area to avoid the feeling of image segmentation, as shown below.

Typical flexographic effect of the target image

One solution to these challenges is to use Hybrid AM hybrid AM screening technology, which increases the size of the highlight area by adding or adding colors without sacrificing the authenticity of the image. It has the effect that it can reduce or eliminate the obvious transition from the ink area to the blank area.

The Hybrid AM algorithm uses the FM screening technology to limit the minimum dot size, avoiding the use of tiny dots, that is, controlling the tone by changing the number of dots, not by changing the dot size. To control (AM).

The following image shows the concept of hybrid AM hybrid AM screening technology. In Figure 1, the image shows a typical flexographic result. The range of gradation is compressed. In the highlight part, there is a very clear transition from the ink area to the non-ink area.

In Figure 2, by using Hybrid AM mixed AM screening, you can add a minimum point on the plate, and randomly remove some points in the highlight area to avoid any extra colors.

Figure 1: Target/Flexo

Figure 2: Target/Hybrid AM Screening

Hybrid AM screening is not a new concept. However, in the past, it was not as omnipotent as one would expect because of the lack of realism in the smoothness of the screening, which produced visible grainy and streaky highlights. The lack of realism and consistency of the cable is due to the limitation of the screen of the highlighting area of ​​the highlight area, and as a result, the smooth structure of the FM screening technology cannot be produced. There are several Hybrid AM screening devices on the market, but they are completely different. Although the basic principles are the same, the smoothness of the screening depends on how the screening device establishes the network lines in the highlight area.

After studying the related advantages and disadvantages of the different Hybrid AM algorithms, Creo thinks that using a hybrid dot size can achieve more realistic copying, effectively eliminating the inconsistency between highlight areas and transition areas. In addition, the same screening principle can also be used for the darker portion to facilitate minimizing the apparent transition of the halftone portion to the solid portion. The traditional Hybrid AM screening uses a fixed-sized dot in the FM screening part of the highlight area; this leaves a hole in the AM screening grid, resulting in inconsistent replication and variegation.

(to be continued)