By asking one question three times over and answering a few others, specifying anilox rolls for a new multi-color die cutter or flexo folder gluer can be done easily. This is true for any flexo printer in the corrugated market, no matter the size.
Asking for a committee of pertinent vendors is the first step. It will include the ink, plate, and roll suppliers. This committee will ensure correct information during the decision-making process, drastically lighten the burden involved in acquiring necessary information and experience, and grow vendor relationships for the future.
Once this is accomplished, it’s time to look at the machine. The common request for new machines is twofold: ability to print both craft solids and brown box type work modeled white, and ability to print 85 line on clay-coated substrates. Unfortunately, there is no set of anilox rolls that can run the full gamut of graphics and substrate range. There are, however, available products that provide a wider latitude of print capabilities within a given set of anilox rolls.
[wpspoiler name=”With this in mind…” ]it’s important to make a preference choice in the characteristics of this new machine.[/wpspoiler]
In other words, it is necessary to prioritize between print optimization or versatility. Choosing optimization means taking a set of graphics, inks, and substrates, and then running a banded roll test to determine which roll’s cell count and volume perform optimally for that set. If versatility is the goal, the search changes. In this case, it becomes a hunt for print characteristics that achieve the greatest results for all substrates, whether it’s clay-coated, uncoated white, and/or craft.
With this knowledge, the questions to answer before deciding how to proceed are these:
- What are the substrates that will be printed on?
- Which inks will be used?
- Are they designed to be run in a vacuum-transfer machine?
- What is the drying capacity?
- Are there even dryers?
- What speeds need to be run?
- What are the graphics to be printed?
- What is the mix – what are the percentages of each type of graphic and substrate used?
Once these are answered, any decisions should show preference to the greater portion of the business mix. The components should allow the setting up and running of the highest percentage to be where the efficiency lies. When running any specialty work, the lower percentage, adjustments can be made to achieve adequate running characteristics.
The means to answering the necessary questions with incredible accuracy is a banded roll trial. These tests provide detailed data that allows for decision-making to become less about estimates and more about definites. A banded roll trial will point out the direction leading to a machine reaching maximum capability right off the bat.
This is the stage where anilox roll cell count and volume combinations can be selected. The most important focus in choosing anilox rolls is the cell volume for the particular substrate. All substrates accept ink differently. Some are absorbent, some are not. This is a critical factor. A cell count that best matches the desired cell volume should be selected. In general, for craft substrates, the volume range needs to be between 7.5 and 8.5. For modeled white substrates, it should be in the 6.0 to 7.5 range. And for a clay coat, it will be down around 3.5 to 5 BCM.
Choosing the right rolls should not be a game of guesswork or feel like an impossible task. I hope this has been helpful in providing some general information with regards to your decisions. If you have any further questions, feel free to reach out to me directly. My contact information can be found at www.binghamflexoservices.com.