Have you had issues with the adhesion of the ink on coroplast?

Hi,

I'm having this issue with the adhesion of the ink on some 1/2" coroplast. The coroplast id fine since its a printable one sold by GRIMCO but the result has been awful. At first glance, I thought it was that the bubbles came because it was oil from fingerprints interfering with the adhesion, but then all the material start pooping out (see video)

I've read that ink expires, but how can I know what happened? should I retrieve all boards and reprint with new ink?

one solution was to clean the boards with alcohol before printing to avoid the oil scenario but after seeing how all peel off today I'm frustrated. It's this HP FB550 a problem or just our process?

Thank you
 

Greg Kelm

New Member
Most likely just the media you're printing on, but how is ink adhesion on other substrates? Do you have any Dyne test pens?
 

Gino

Premium Subscriber
It's due to lack of adhesion to the surface. There's a myriad of reasons. The corona could be gone from the Cor-X to improper lamp exposure to a bad profile or wrong profile.
 
I've had that issue on a random bit of coro (2-4 signs out of ~30 signs, run 10up) in the middle of a run. I use a product called AP2155 by Supply55 to clean dirty boards which is also an adhesion promoter and it seems to work pretty well (possibly better adhesion than when I'm using "clean" boards).
 
I've had that issue on a random bit of coro (2-4 signs out of ~30 signs, run 10up) in the middle of a run. I use a product called AP2155 by Supply55 to clean dirty boards which is also an adhesion promoter and it seems to work pretty well (possibly better adhesion than when I'm using "clean" boards).

we use that product for acrylics... never for coroplast? Do you think it’s a good idea to add more intensity to the UV lights?
 

Gino

Premium Subscriber
Have both ours set to full blast on just about every profile, except uni. Cor-X needs plenty of UV, so lessing the lamps could be a gig problem, especially if your inks are well-suited for Cor-X. Some machines just plain don't like Cor-X.
 

Troy Lesher

Merchant Member
Hi,

I'm having this issue with the adhesion of the ink on some 1/2" coroplast. The coroplast id fine since its a printable one sold by GRIMCO but the result has been awful. At first glance, I thought it was that the bubbles came because it was oil from fingerprints interfering with the adhesion, but then all the material start pooping out (see video)

I've read that ink expires, but how can I know what happened? should I retrieve all boards and reprint with new ink?

one solution was to clean the boards with alcohol before printing to avoid the oil scenario but after seeing how all peel off today I'm frustrated. It's this HP FB550 a problem or just our process?

Thank you
Several factors influence adhesion on coro and acrylic substrates but the most important one is the inkset itself . too rigid of an ink has a strong tendency to peel
There are several product out there to promote adhesion, which ads another step and added expense.

We have developed an inkset that has absolute adhesion to coroplast regardless of corona or dyne level
and it has the same adhesion on the regular acrylic as well (Which is $75-$100 a sheet less expensive for the "Digital" Acrylic.)

Lamps can play a roll, especially the older mercury vapor lamps, as they can gradually loose their curing ability unlike todays LED lamps with a consistent cure , having said that some LED lamps are better than others, power of wattage, frequency etc.

Check it out. Here is our high adhesion inkset for our Trufire platforms specially dialed in for shops that do a lot of coro, acrylic and the like.
The adhesion on this ink is absolute.

https://www.dropbox.com/s/2h499tlqmz76yer/Scratch test.wmv?dl=0

One caveat, we do not sell just the ink... However I am making some serious opportunities for new customers call me anytime
 

Boudica

I'm here for educational purposes.
Hi,

one solution was to clean the boards with alcohol before printing to avoid the oil scenario but after seeing how all peel off today I'm frustrated. It's this HP FB550 a problem or just our process?

Thank you

That should be your first solution. I always wipe down all substrates with alcohol - with the exception of foam core. Whenever I have ink peel off coro in spots - it's because I missed a spot when wiping down the sheet.
 

FireSprint.com

Trade Only Screen & Digital Sign Printing
We found Kolorcure Metal and Glass Primer would help with this as well. While there are alot of reasons why this could happen, the majority of the issue is your material. Corrugated plastic has a shelf life. That's an old sheet and the Dyne Level has surely dropped.

You need to experiment with different primers until you find something that works. You might even try a few of the thinners/solvents you can find in the paint section of the hardware store.

On the other hand, if you want us to print it for you and end all the headache we sure can -
Digital 10mm Coro - https://www.firesprint.com/yard-signs-10mm-heavy-duty-digitally-printed/
Screen Printed 10mm Coro - https://www.firesprint.com/yard-signs-screen-printed/

Join us!
 

Zach Starr

Head of Printing Operations
Hi,

I'm having this issue with the adhesion of the ink on some 1/2" coroplast. The coroplast id fine since its a printable one sold by GRIMCO but the result has been awful. At first glance, I thought it was that the bubbles came because it was oil from fingerprints interfering with the adhesion, but then all the material start pooping out (see video)

I've read that ink expires, but how can I know what happened? should I retrieve all boards and reprint with new ink?

one solution was to clean the boards with alcohol before printing to avoid the oil scenario but after seeing how all peel off today I'm frustrated. It's this HP FB550 a problem or just our process?

Thank you

Try using a different coroplast for any other supplier. It could be the coating on the media as most of the big dealers buy media from China. You could also try changing the UV lamps on your HP.

Last solution would be to change the printer, as HP UV Printers are very old technologies, and media manufacturers are now trying to produce materials as per new specifications, for High Speed Curing, and Latex Technology. I have noticed issued like these on my HP when it was coming to its end of life. Alot of maintenance and curing issues.
 

FireSprint.com

Trade Only Screen & Digital Sign Printing

ikarasu

Active Member
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