White Ink Adhesion

[Bxtr]

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, are you having any luck with any materials?
Or can you get sample sheets of different products than you normally use from your vendor?
Are you putting white down when printing everything or just dark/clear substrates?
On white material, if we start seeing finger prints we will lay down 10-20% white ink as we are printing color. We never print over 30% on the lamps, I know when printing MDO or ACM or Aluminum. We could go higher but if it's curing good on everything we don't see a point to readjust for each material just to have an operator forget and destroy an expensive sheet.

The materials we have printed on without issue have come from multiple vendors. We have printed on the digital ready and non-digital ready and the huge difference for us the was only the acrylic unless used with promoter.

 

[Patrick Farrell]

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

I guess that does make sense. That's how I usually do my Haptic print files. I never made the connection though. Most of my Haptic test prints are smaller in size due to the longer print times and copious amounts of white ink that has to be laid down first to gain the texture. I will definitely give that a shot. Thanks for the input.

 

[Patrick Farrell]

Patrick, are you having any luck with any materials?
Or can you get sample sheets of different products than you normally use from your vendor?
Are you putting white down when printing everything or just dark/clear substrates?
On white material, if we start seeing finger prints we will lay down 10-20% white ink as we are printing color. We never print over 30% on the lamps, I know when printing MDO or ACM or Aluminum. We could go higher but if it's curing good on everything we don't see a point to readjust for each material just to have an operator forget and destroy an expensive sheet.

The materials we have printed on without issue have come from multiple vendors. We have printed on the digital ready and non-digital ready and the huge difference for us the was only the acrylic unless used with promoter.

That's where it gets maddening. I printed a job on 12mm Black PVC (stock not digitally rated). Adhesion failed. We turned the lamps down from 100% to 70% and it worked great. We just ordered some dyne pens. I'm really hoping this helps with the prep. If i know a sheet is going to be a problem going in, I can take the steps to make sure it doesn't fail. Have you had any experience with Bondaid 2? We picked up a bottle of the acrylic AP and it goes on like super glue. I get maybe 3 swipes of a cloth and it hardens. AP3155 doesn't do that.

 

[rcali]

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.

I also have an Oce Arizona, I get it!

 

[ProColorGraphics]

I have been using the AP-2155. I agree the 3155 is nasty!! The 2155 still stinks, but has worked great for me on anything from coroplast to acrylic to ACP.

 

[Bxtr]

That's where it gets maddening. I printed a job on 12mm Black PVC (stock not digitally rated). Adhesion failed. We turned the lamps down from 100% to 70% and it worked great. We just ordered some dyne pens. I'm really hoping this helps with the prep. If i know a sheet is going to be a problem going in, I can take the steps to make sure it doesn't fail. Have you had any experience with Bondaid 2? We picked up a bottle of the acrylic AP and it goes on like super glue. I get maybe 3 swipes of a cloth and it hardens. AP3155 doesn't do that.

I've only used the AP-3155 on acrylics, even then if you aren't printing heavy saturation or solid colors 1st surface you can see they wipe marks/hand prints.
Although it takes longer we've routed acrylic and just used the promoter on the edge and printed with bleed, if you have multiples you can always set up a jig.

 

[marunr]

Patrick, I'm just curious. We have the VR5D and always print on pieces that have been cut or routed first and have not had an adhesion problem. If printing first we have not been able to cut or router through the ink on acrylic without it flaking off. We can laser it however. PVC does not present the same problem, but I have never been able to get the CNC operators to keep the debris off of the pre-printed parts enough to be satisfactory unless they are re-masked after printing, so I would rather make a jig anyway.

 

[Patrick Farrell]

Patrick, I'm just curious. We have the VR5D and always print on pieces that have been cut or routed first and have not had an adhesion problem. If printing first we have not been able to cut or router through the ink on acrylic without it flaking off. We can laser it however. PVC does not present the same problem, but I have never been able to get the CNC operators to keep the debris off of the pre-printed parts enough to be satisfactory unless they are re-masked after printing, so I would rather make a jig anyway.

We do a fair amount of printing to the finished size. It does seem to help with the decreased amount of handling it has to go through. The fact that it doesn't have to be masked I'm sure helps a bit too. We actually haven't had any issues lately. We picked up a set of DYNE pens and this whole debacle has really helped me sell the use of print grade material to the project managers. As for the operators maintaining debris free parts......I feel your pain. We are doing a job printing and building Tempurpedic displays. 12mm black PVC laminated and printed both sides with Oracal white vinyl and 3 nested parts. I printed 60 sheets so 180 parts. Each 4'x8' sheet took approx 30-35 minutes to print both sides. I am now being told that there were no bad parts but somehow I am short 6 sheets worth. Hmmmmm......I laid down a layer of roll foam between each sheet. I wonder what happened lol?

 

[Sabernathy]

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.

I know I'm a little late but please be sure to properly ventilate and use a mask. I ended up in the ER from breathing the vapors of AP3155. Super dizzy, nausea and stroke level blood pressure.

 

[bowtievega]

When printing large sheets of back printed acrylic we will spray Grip Guard VPS-1 adhesion promoter on the entire sheet prior to printing. Works great, don't have any issue with chipping when that sheet goes to the router for cutting.

 

[Patrick Farrell]

I know I'm a little late but please be sure to properly ventilate and use a mask. I ended up in the ER from breathing the vapors of AP3155. Super dizzy, nausea and stroke level blood pressure.

Shit. Sorry to hear that bud. We have 2 ventilated paint booths. I use them when I have to use it.