White Ink Adhesion

[Patrick Farrell]

I run a VK300D-HS. 5-Head setup so only 1 channel of white.
I use the Vanguard High Adhesion inks.
The issue that I am running into is this:
We print just color on a piece of white material. No adhesion issues.
Doing the same print with a layer of white under it, fails 7/10 times.
I clean everything with denatured alcohol.
I have tried increasing the passes.
lowering lamp intensity to allow more time for the ink to adhere before curing.
I largely print on standard PVC, ACM, Acrylic etc...
I know that there are digitally rated materials for this specific purpose. But that still doesn't explain why only the white doesn't stick.

Any helpful links or tips you have would be greatly appreciated. There's not much out there for a support group for these printers,
I also have pictures of settings and failures if they are wanted.

 

[Signarama Jockey]

I use an EFI, so I don't have the same machine you do, but I would be curious to see the failures look like. Just the whole print shrivels up or flakes off?

Would you mind posting a picture?

 

[Patrick Farrell]

Here is some 1" Acrylic and 3mm Black ACM

 

[netsol]

HOW IS IT FAILING?
is the issue ADHESION from white ink to substrate?
or COHESION from colored ink to white ink?

my first attempt would be either a primer/adhesion promoter if it is adhesion from white ink to substrate

or

allowing a longer time to cure before printing colored inks to the white

 

[Signarama Jockey]

Strange. Am I seeing this correctly? Is the white base coat just straight up flaking off? It looks like these pieces are separating from the substrate altogether and taking the print with them.

You said you were wiping everything down with alcohol; this might be a stupid question, but you give it time to dry before you print, right? You said that you have no problems with other colors, so I'd assume you were, but I have to ask.

I'd be curious to see if just plain white flakes off. Have you done that test? Maybe the white ink is bad? Wonder if it has or needs to be agitated (swirled not shaken). The issue seems to center around the white.

 

[chrisphilipps]

My guess is you are over curing it. How low did you make the UV Power?

 

[Bxtr]

I run a VK300D-HS. 5-Head setup so only 1 channel of white.
I use the Vanguard High Adhesion inks.
The issue that I am running into is this:
We print just color on a piece of white material. No adhesion issues.
Doing the same print with a layer of white under it, fails 7/10 times.
I clean everything with denatured alcohol.
I have tried increasing the passes.
lowering lamp intensity to allow more time for the ink to adhere before curing.
I largely print on standard PVC, ACM, Acrylic etc...
I know that there are digitally rated materials for this specific purpose. But that still doesn't explain why only the white doesn't stick.

Any helpful links or tips you have would be greatly appreciated. There's not much out there for a support group for these printers,
I also have pictures of settings and failures if they are wanted.

Hello Patrick,

We have a VK300D-HS 6-head setup so 2 heads of white ink.
The only issue we've ran into with ink flaking off is print on standard clear acrylic without using an ink promoter.
ACM (Maxmetal), PVC (Palight) we don't have any issues with. We've been buying digital ready acrylic when printing ADA signage.
We keep our lamps just under 30% otherwise it will start to warp the material.

I hope this helps, if not please reach out.

 

[Grizzly]

Acrylic is notorious for adhesion issues. We have to use a primer on non-digital acrylic.
I'd suggest switching to a Digital Acrylic such as OptixDA (Digital Acrylic) or another brand that specifies that it is digital ink receptive.

Jeremy

 

[Patrick Farrell]

Hello Patrick,

We have a VK300D-HS 6-head setup so 2 heads of white ink.
The only issue we've ran into with ink flaking off is print on standard clear acrylic without using an ink promoter.
ACM (Maxmetal), PVC (Palight) we don't have any issues with. We've been buying digital ready acrylic when printing ADA signage.
We keep our lamps just under 30% otherwise it will start to warp the material.

I hope this helps, if not please reach out.

It seems so intermittent. We initially had our lamps @ 100. The issue as it was explained to me then, was that it was curing before it had a chance to bond with the material. We turned the lamps down to 70% and things seemed to work out better over all. Now we run into the same issue and I was subsequently told that my lamps were too low and to turn them up to 100%. The ACM we ran half the sheet laid up great. The other half (bottom half) is literally peeling off as if it was printed on the backside of the low tack paper mask.
The media WAS print ready I was later informed. Normally we do not have an issue. I did a small test print on a piece of 3/8 acrylic (1st surface) put a section of high tack paint mask on it and ran it through the laminator. I ripped the mask off and everything was still there. We print on 6mm PVC daily. No issues. If white is laid down, it's 50-50 most times. It's the inconsistencies that are driving me nuts.

 

[Patrick Farrell]

HOW IS IT FAILING?
is the issue ADHESION from white ink to substrate?
or COHESION from colored ink to white ink?

my first attempt would be either a primer/adhesion promoter if it is adhesion from white ink to substrate

or

allowing a longer time to cure before printing colored inks to the white

It is 100% adhesion. The color only peels off if there is white is laid down first. We have used adhesion promoter on ACM. Oddly enough on a piece that was already digitally rated. It failed.

 

[Patrick Farrell]

Strange. Am I seeing this correctly? Is the white base coat just straight up flaking off? It looks like these pieces are separating from the substrate altogether and taking the print with them.

You said you were wiping everything down with alcohol; this might be a stupid question, but you give it time to dry before you print, right? You said that you have no problems with other colors, so I'd assume you were, but I have to ask.

I'd be curious to see if just plain white flakes off. Have you done that test? Maybe the white ink is bad? Wonder if it has or needs to be agitated (swirled not shaken). The issue seems to center around the white.

Hahaha. Yes it is dry when the printing starts. I actually just did that test friday and let it set over the weekend. I'll be checking in on it shortly.

 

[Patrick Farrell]

My guess is you are over curing it. How low did you make the UV Power?

Well, that's where it gets infuriating. Initially my lamps were @100%. Had been for some time with little or no issues. We started have adhesion problems. I contacted Vanguard and they told me that my lamps were too high that the ink was curing before it had a chance to bond with the material. Made perfect sense. We turned it down to 70% and again, it worked great for a time. Then it happened again. Contacted Vanguard. They told me that my lamps were too low and to turn them back up to 100%. I took a snip of the first email that stated 100% was too high and added it to the help ticket email. I have not heard back from them since I sent it on Friday.

 

[rcali]

I run a DCS7200Z, which is a different headache all together but here are somethings I have to do to keep adhesion/ test and make sure adhesion will work:

1) Dyne testing. There are these ink pens that you can use to test the surface energy of your substrates to make sure your ink will stick. I don't know how to go about procuring the surface energy number for your inks specifically but for my ir2 inks the number is about 40 dynes, so I test my substrates with these pens and if the surface tests at 38-44 dynes, I know my ink will stick alright.
2) On my printer, I throw down a layer of clear ink before anything else (after adhesion promoter but before any colors/white) because the clear ink, at least for my system, acts like a pretty solid glue.
3) I have taken to getting my substrates painted with automotive urethanes before printing, because that type of paint and my inks have a similar chemistry and like to stick to each other well. (I mostly do this for aluminum so it may not apply to you in this instance)
4) Adhesion promoter, its stinky and gross but it makes my ink want to grip to my substrates.
5) I have to remind everyone not to adhesion test for at least 24 hours because the bond of the ink needs to cure to seriously see if it will stay on. (I am saying this for my own sense of sanity, you probably know this, but I have to remind my department not to pick at my prints right after I print them because of course they won't stick if they're messed with 10 seconds after they come off the bed.)

 

[Patrick Farrell]

I run a DCS7200Z, which is a different headache all together but here are somethings I have to do to keep adhesion/ test and make sure adhesion will work:

1) Dyne testing. There are these ink pens that you can use to test the surface energy of your substrates to make sure your ink will stick. I don't know how to go about procuring the surface energy number for your inks specifically but for my ir2 inks the number is about 40 dynes, so I test my substrates with these pens and if the surface tests at 38-44 dynes, I know my ink will stick alright.
2) On my printer, I throw down a layer of clear ink before anything else (after adhesion promoter but before any colors/white) because the clear ink, at least for my system, acts like a pretty solid glue.
3) I have taken to getting my substrates painted with automotive urethanes before printing, because that type of paint and my inks have a similar chemistry and like to stick to each other well. (I mostly do this for aluminum so it may not apply to you in this instance)
4) Adhesion promoter, its stinky and gross but it makes my ink want to grip to my substrates.
5) I have to remind everyone not to adhesion test for at least 24 hours because the bond of the ink needs to cure to seriously see if it will stay on. (I am saying this for my own sense of sanity, you probably know this, but I have to remind my department not to pick at my prints right after I print them because of course they won't stick if they're messed with 10 seconds after they come off the bed.)

We are looking into the dyne pens. I believe the dyne level of our inks are relatively similar. Unfortunately we only have the setup for CMYKW. We have a bottle of AP3155 and yeah it smells awful. We haven't used it since we purchased the VK300D. The High Adhesion inks were supposed to have eliminated the use of it. It did for some time. It's just more recently that we have been having issues. Vanguard has been helpful so far, but they also seem to be perplexed by the adhesion issues.

 

[rcali]

We are looking into the dyne pens. I believe the dyne level of our inks are relatively similar. Unfortunately we only have the setup for CMYKW. We have a bottle of AP3155 and yeah it smells awful. We haven't used it since we purchased the VK300D. The High Adhesion inks were supposed to have eliminated the use of it. It did for some time. It's just more recently that we have been having issues. Vanguard has been helpful so far, but they also seem to be perplexed by the adhesion issues.

Adhesion promoter, at least in my testing, adds about two dynes to a surface. Has your substrate vendor changed? Or maybe they changed how they make your substrate?

For instance, my adhesion on white coated 0.40 aluminum (sign blank, enamel coated aluminum) was good for years, until 2023. The ink started chipping off new prints and taking the white coating with it, I didn't have an old batch of aluminum to test but we still wonder in our shop if the manufacturing process changed and with that change, so did my adhesion. Thus why I get my metals painted before I print them now.

I also have AP3155, but I tend to use the Low odor version instead (it still stinks though lol) I-UV-ADHPR2-200. Mix 30% promoter with 70% 90proof IPA.

Adhesion issues can be perplexing for sure, especially when substrate chemistry and ink chemistry are so guarded because of proprietary rules.

I'm attaching my dyne testing chart, I don't know that it will be super useful considering I'm not privy to the names of my manufacturers (I don't do the material ordering)/ you may not even use the same products.

 

[Patrick Farrell]

Adhesion promoter, at least in my testing, adds about two dynes to a surface. Has your substrate vendor changed? Or maybe they changed how they make your substrate?

For instance, my adhesion on white coated 0.40 aluminum (sign blank, enamel coated aluminum) was good for years, until 2023. The ink started chipping off new prints and taking the white coating with it, I didn't have an old batch of aluminum to test but we still wonder in our shop if the manufacturing process changed and with that change, so did my adhesion. Thus why I get my metals painted before I print them now.

I also have AP3155, but I tend to use the Low odor version instead (it still stinks though lol) I-UV-ADHPR2-200. Mix 30% promoter with 70% 90proof IPA.

Adhesion issues can be perplexing for sure, especially when substrate chemistry and ink chemistry are so guarded because of proprietary rules.

I'm attaching my dyne testing chart, I don't know that it will be super useful considering I'm not privy to the names of my manufacturers (I don't do the material ordering)/ you may not even use the same products.

We are going to do some tests with the AP3155. Also a good thought on manufacturing changes. That is something that I haven't actually considered yet. Thank you for the list as well. It will no doubt come in handy.

 

[Christian @ 2CT Media]

So we had this issue in the past with the standard inks. Have you tried running white as it's own print file and then the color in a second run?

Turn your lamps down on the white run, then back up on the color

 

[White Haus]

Adhesion promoter, at least in my testing, adds about two dynes to a surface. Has your substrate vendor changed? Or maybe they changed how they make your substrate?

For instance, my adhesion on white coated 0.40 aluminum (sign blank, enamel coated aluminum) was good for years, until 2023. The ink started chipping off new prints and taking the white coating with it, I didn't have an old batch of aluminum to test but we still wonder in our shop if the manufacturing process changed and with that change, so did my adhesion. Thus why I get my metals painted before I print them now.

I also have AP3155, but I tend to use the Low odor version instead (it still stinks though lol) I-UV-ADHPR2-200. Mix 30% promoter with 70% 90proof IPA.

Adhesion issues can be perplexing for sure, especially when substrate chemistry and ink chemistry are so guarded because of proprietary rules.

I'm attaching my dyne testing chart, I don't know that it will be super useful considering I'm not privy to the names of my manufacturers (I don't do the material ordering)/ you may not even use the same products.

Do you happen to have more details about the "Wonder Cleaner" on your list?

 

[rcali]

Do you happen to have more details about the "Wonder Cleaner" on your list?

Delta Foremost 2153 Wonder Cleaner

(I use it when I do not want to run the risk of melting paints/ substrates.)

 

[White Haus]

Delta Foremost 2153 Wonder Cleaner

(I use it when I do not want to run the risk of melting paints/ substrates.)

Cool, thanks! I'm always on the hunt for new materials to prep substrates before printing. Our Oce Arizona is very finicky when it comes to prep.