As we begin 2025, there are, no doubt, several companies kicking off inkjet integration projects to shift to or combine digital printing or decoration with analog printing. And this is a good thing. We are in the midst of an industrial inkjet revolution. Inkjet has already successfully been integrated into display graphics, ceramic tile, product marking, and moving steadily into textiles and packaging and well everything! It’s where I play and I love it. So, as we start the year I thought I would share my advice with hopes this helps organizations planning out there 2025 strategic digital projects. It’s a combination of advice as well as a warning! So here goes.
Over the years I have routinely worked with companies who had the following vision: Integrate a digital printing solution into an existing analog printing or manufacturing process. Ideally, the client would search out a digital “printbar”, if you will, which could be easily mounted into an existing product line. This would add to or even replace analog print stations. Variable data adds value for everyone! Okay, I am with you. Of course, we need to make sure that the ink delivery system can maintain adequate feed rates to the printheads. Makes sense. And let’s be sure the printhead has the resolution and throughput we need for required productivity. Absolutely. And to keep things simple, the project scope will be limited to use an “off the shelf” ink or coating solution. This would simplify the project, reduce cost and the amount of development work.
Uh oh…
I am one of those R&D guys that sometimes learns things the hard way. And this was one of them. After all, if you look for an integratable (is that a word?) printbar that has an approved ink to go along with it, you are going to find it. And I used to think, “Maybe it will work!”
But not any more…
Here are just a few of the problems I have run into when trying an “off the shelf ink” in an industrial inkjet application and some common strategies to overcome those problems which do NOT include “ink development”.
The ink isn’t dry!
Since we are not getting into the chemistry, maybe you're laying down too much ink. Maybe the ink and all that glycol was designed to absorb into a substrate like uncoated paper... Maybe your press speed is faster than what the ink was designed for. Can you slow down? Perhaps your curing system or ovens are under powered for the new ink. If this is the case you can reengineer your press or reduce total ink coverage.
The ink is flaking off!
You are able to dry the ink but it's not sticking to your substrate. You’re going to have to explore options along the lines of substrate and pretreatment. Can you use an alternate substrate? Can you add treatment like corona to boost surface energy? How about adding a primer? Maybe it’s just in winter time the ink is brittle on those truck side curtains! Hard to work with that one, I’ve tried.. I have seen some companies try to “under cure” UV inks to boost adhesion! Please don’t.
Now the ink stinks!
The raw materials used in the ink have a lingering odor that isn’t good for automobile interiors on those hot sunny days…. Even if you want to add an odor mask, you're talking about modifying the ink… Try boosting cure or encapsulating ink in an overvarnish.
The product is failing for chemical migration!
Turn up the curing if you can. Slow down the press. Or you can try adding a floodcoat overvarnish to keep residual from leaching into the fruit. Remember, your kind of stuck with the ink.
The ink is too expensive!
Try to negotiate a lower price with the vendor. Do they have a lower price ink which is qualified in the digital printbar? I know YOU don’t need automotive grade pigments for product packaging, but this is a universal ink!
I can’t hit my required color gamut!
Bring in some profiling expertise. Is there an “off the shelf” orange and violet so you can hit the gamut you need? Is there another inkset to try?
The ink has no durability!
This is a universal inkset so it needs to be softer for a variety of applications and roll to roll substrates. Try another inkset. Have your team run ladder studies on cure power. Try ink limiting. Add an overcoat to protect your sheets from that downstream lead edge feeder!
I can’t laminate or overcoat the ink!
This is a universal inkset so it contains waxes and silicone for slip. I guess it may not behave well with your adhesive for laminate flooring. Can you explore new adhesives?
The ink is foaming!
Study the ink system. Where is the air coming from? Your single pass application requires recirculation to ensure air doesn’t deprime heads. Can you dial down recirculation or tank agitators? Adding a defoamer could help but we are not getting into ink development, remember?
The ink is misting all over the press!
I know your corrugated sheets are shaped like Pringles but try reducing the print gap. Engineer an extraction system to remove ink mist from print zone. We are not getting back into ink and printhead studies either. That is out of scope.
The printheads are clogging constantly!
Engineer a closed environment to protect the heads. Add climate control and humidity to your plant. Build a robust head cleaning system in the press. Create SOP’s to clean head every few hours as needed for quality.
Reliability and uptime are too low.
Run extensive operating windows on every print mode. Identify the ideal environment for the press. Temperature, humidity, static, print gap, substrates, pressroom cleanliness should all be evaluated.
The list goes on..
These are just a few of the ink issues that come up when integrating inkjet into an existing manufacturing process. If you don’t include ink development as part of your engineering plan, I promise you will have to add it later. I am not saying ink development will solve all the problems above. To be clear, it will not!
To solve these types of issues, the most robust solution will be a combination of engineering, process, and chemistry!
Now good luck to you in 2025 and don’t forget to include Ink Development in your project scope!
-Terry
Ps. If you are planning a digital project; or if you need help with an existing inkjet project, reach our anytime.
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