i-Pro (HD Process)
High definition flexographic printing with the i-Pro
The i-Pro engraving is specifically designed deal with ‘high definition’ printing in flexography. The cell management of this engraving was designed in order to increase release characteristics but maintain control. This open cell management mean that line counts are significantly finer 0.4% dots. Within the wide-web application the i-Pro’s open cell management means that at high speeds of 500m/pm there is no ink starvation that usually would cause inconsistent and low densities.
The iPro engraving allows printers to harness the vivid colours and increased optical densities of HD printing whilst reducing dot gains and printing fin highlight dots on long runs at high speed.
Whilst Sandon were trailing engravings it became apparent that conventional 60° engravings did not have the capability to meet the necessary targets of both optical density and fine highlights. The 60° engraving might pass for some, but not Sandon. Sandon were determined to find an engraving that could be used in high speed, reduced dot gain, had consistent optical density and could maintain the fine print neccesary from HD printing.
A parabolic engraving is the answer for many to the questions posed by HD print, it traps proportionally more ink in its cells which creates a more inconsistent ink release and in turn, inconsistent dot gain and makes anilox more like to create dot bridging in highlight areas.
Furthermore, it was found that conventional 60° engravings lose optical density in flexible packaging when running in excess of 500m/pm.
All of this goes to show that, even given the fact that parabolic cells may physically carry more volume that standard engravings it in fact only leads to more ink becoming trapped in the cells and increased the issue of ink starvation and results in poor and inconsistent optical density.
As testing extended, it was clear that even when using free open flowing cells in a conventional engraving and the optical densities were good, they still did not have the required control element to maintain the fine dot necessary for HD printing.
Dots bridging due to poor cell control element of anilox cell structure.
During the development programme at Sandon, it became clear that a new type of engracing woukd be needed to meet the very specfici requirement of HD printing. From this, the iPro was born. The iPro combines the control elements of conventional 60° engraving