Why inkjet projects struggle and new possibilities to revive them

Aktualisiert: 14. Juli 2021

Some print processes never reach a mature state before consuming their total budget. We added optical analysis and image editing software tools to the print processes to revive failed process developments, print engines and projects.

Camera inspectiom of the print result
Camera inspection of the print result
 

Since the founding of n-art-m, we were so fortunate to take part in the development of a great variety of different industrial inkjet applications – including the matching hardware and inks. Each development was for a different market and each one was of different scale.

Even though a vast majority of the projects were successful in developing an industrial print process, we also got approached by customers who already put development effort in digital applications, but ultimately failed. Mostly, these customers were at a stage where the existing budget was consumed and the procurement department was sceptical of any new investments in inkjet technology.

Out of these projects, most were at a very advanced state. Just an improvement in quality or reliability was necessary. These last meters however made the crucial difference between a solution with added value to a market (and an extended customer base) or a project that needed to be abandoned.


Common reasons, why inkjet projects struggle

With these projects we saw, that it was hard for the customer to pinpoint the exact reasons for bad print results or missing reliability. It takes different areas of expertise for a successful realisation of an inkjet project. That way, when you are trying to implement a print process, you can end up with lots of different opinions and requirements from chemists, printhead manufacturers, ink manufacturers, system integrators, electronics providers, inkjet consultants etc. All these points of view can be hard to combine, or even contradict each other.

In the worst case, everyone ends up just shifting the blame.

For the customers it was also difficult to accept, that experience gained in the lab doesn't transfer to production conditions. Problems that are identified at these very late stages of a project are most certainly the end of it, since they require huge reinvestments to fix. The project then fails to reach that high quality the market demands.

But we think it is not the time to throw that old print system that never made it to market or that print process you almost developed in the bin just yet.


Don’t expect your print process and hardware to be perfect, we have a solution ready in case it isn’t.

From these experiences, we made the decision to focus our development efforts and expand our portfolio by optical analysis and digital image-editing tools.

Of course, major factors like the printing hardware and the chemics of the print fluid are still very important for the success of a print process development. But to make these last steps to great print quality and reliability, we are convinced that software solutions make a real difference.

Here are the three main aspects we have identified as levers for improvement.

Printed grid on three-dimensional substrate
Printed grid on three-dimensional substrate

Analysis before printing

By having an optical inspection just before printing, the substrate’s condition and conveying can be analysed:

· Are there any bent edges?

· Does the shape of the substrate stretch?

· Does the substrate colour differ from the standard?

· Where is the predetermined printing area located in relation to the print system?

· Is there any unusual form or structure that the print system should adapt to?


The optical analysis before the printing offers great possibility to adapt depending on unique factors. By taking the analysis data in consideration to edit the image data, the placing of a droplet can be changed depending on variations in the substrates. It also offers the ability to change the droplet itself depending on the desired colour that needs to be achieved.

As a real-life example: A customer approached us with an inaccurate substrate conveyer. It was not possible to get the conveyer to the accuracy that was needed, and he was therefore missing the print quality required to sell his printed product. He was looking into costly ways to improve the accuracy of the hardware, BUT inkjet is designed to offer different solutions: Since we are printing digitally, we should take advantage of being able to adapt image data quickly and depending on conveyer and substrate conditions.

With the inspection we were able to improve the print quality and therefore make the printed product hit its full market potential.

Drop on nozzle plate
Drop on nozzle plate


Monitoring the system

By having sensors and a camera inspecting the print system, it is possible to gain a lot of reliability in a print process. Collecting values and image information, information on environmental conditions and the output of a print process can be a game changer.

Let us explain:

Sometimes a print system only struggles when the humidity is a few percentages higher, or the substrate adhesion of an ink is not great when a certain temperature is not reached inside the fluid supply for a certain period of time. To find these correlations and to suggest ways to get rid of strange behaviours is only possible, if all the information necessary is available and put in relation. Otherwise, the focus for troubleshooting is sometimes shifted and jeopardizes the reliability of a print process.

An example: We had a situation, in which a customer asked for sophisticated ways to recover nozzles of their printer. When considering also the environmental factors we found, that only under certain environmental conditions the build up around a nozzle increased very fast. It just needed more cleaning procedures or an air conditioning to increase the quality of the printed picture and reliability of the process.

Seeing the whole process in a big picture and let AI figure out ways to improve printing behaviour helped us a lot with fragile print processes.

Converging droplets
Converging droplets


Learning from the output of a print system

To inspect the output of a print process in detail – meaning down to individual droplets on the substrate ؘ– and putting it together with collected data is a great way to improve the print quality. Depending on certain phenomena, it makes sense to change the print data, the whole process or just the voltage of a head. But the first step to do so, is to understand print results and causes for inkjet specific print issues.

The solution however does not need to be the same old, same old. Changing the chemics of an ink for a print process is sometimes absolutely necessary, but for some cases it is a better solution to find different ways to split up the print process, customised ways to layer the ink droplets to change the behaviour of the ink on a substrate completely.

Another example: A customer had built a great production line for his product. The whole process was designed neatly, but no matter which ink and which changes to the fluid and pre-treatments he tried, the ink was not building sharp edges. His product was therefore not able to be sold at the price it could reach in a better quality. We inspected the droplets on the surface and found different ways to split up the data into layers. With this analysis we were able to find a process for printing that made sense and was a great solution for this application. Printing outlines first and the filling later was an approach, that we never would have found without beeing able to inspect droplets and their behaviour in detail on the substrate.

Having an eye on what comes out of the printer is a given. But focussing on the right details and inspecting the result down to the droplet and its individual behaviour can lead to new ways of printing.

We are excited about this new chapter in our inkjet development and think there is so much benefit to be made for demanding applications and reviving existing projects with added analysis and data-editing software. It is time that the hurdle to a successful industrial inkjet process is finally lowered

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