UV adhesion

[Donny7833]

Ok flatbed owners. I see a bit of discussion on adhesion to coroplast, I'm interested in what kind of adhesion your getting on Acrylic.

I'm going to ISA far a hard look at a few machines I've gotten sample printed on. Hopefully I'll be able to make a final decision on which machine to go with. I know there are other machines out there, but I'm shopping in the $150K range, give or take.


I sent out files for sampling on the Anapurna M, Fuji Acuity Advance, HP FB950, Vutek QS2000 and the Rastek T660 (only because I heard a rumor there will be a Rastek 4x8 flatbed introduced at the show). I spoke with each machine rep to explain our needs. I made a point to state that good adhesion to acrylic, not PETG or Polycarb, would be a major factor in our machine choice. I handed over the files and waited for samples to show up.

All the samples are in and from what I've seen, the Fuji (IMO) has the better print quality / speed combination. However, adhesion to the acrylic was dismal, looked great but the tape test took it right off. I was told the samples were printed with KO inks and without a promotor. There is another ink set (KI) which is suppose to be better.

To Fuji's credit, they were the only company to supply a sample on actual Acrylic. All other companies supplied either PETG or Polycarb, different animals when it comes to adhesion.

All machines, except the Rastek, supplied coroplast samples and each one had great adhesion and no edge flake when cut.

So, I'm asking if owners of the machines above could chime in on your experiences with acrylic. Good or bad, your input would be much appreciated.

Thanks in advance, Donny

 

[Big Blue]

I have heard bad things about the Rastek....Lots of problems.... The QS on the otherhand I have heard quite different reviews... I have a Press VU UV 200/600sc machine and I love it...aside from a few clogged jets I have had no major problems.... and the QS models are much faster than mine..... We print on Coroplast and acrylic quite often and have had no real issues with either..... If it is cured properly it is good to go.

 

[sjm]

We own a QS3200, adhesion to acrylic is not an issue. When you couple that with the white ink capability that the machine offers it opens a number of new markets for you.

We have printed on virtually everything from ceramic tiles, to glass to formica laminates etc etc quite successfully. Be prepared however as there is a learning curve and finding the right recipe for each substrate will take sometime.

Polycarb for us does pose a problem, specifically in roll form and at 10pt which we must run a specific project with a white ink flood overprint. In order to run this project we have to set the UV lamps at a lower setting (or the polycarb begins to melt) which does leave the inks some what tacky. We work around this by applying a 1.5mil PSA Laminate and everyone is happy.

 

[SignManiac]

I'll see if I can run a test on acrylic for you on our FB950 and let you know the results. I don't normally print on acrylic but I might as well give it a go and see if I can use it more in the future.

 

[Gino]

We have a Dilli 6 color and it prints to everything just fine. We had some early on problems with Cor-X, but have found the happy medium that now works. We've printed to acrylic and poly carb and have no issues with either.

Our biggest problem is we were told we could print directly to MDO. We even printed to some at two demonstrations, but never full sheets. Therein lies the problem, we haven't found any flat enough to go through properly in a full 4' x 8' or 4' x 10'

 

[Tony Teveris]

On the Gerber ion we found it depends on the acrylic and how old it is.
Some brands work better than others. You MUST remove the protective film 24hrs before you print on it. If you don't the adhesion sucks due to the acrylic out gassing.

The digital grade (DA) acrylic that was just released looks promising. Initial test show great adhesion. We got a few sheets in for testing and the adhesion was awesome.

 

[Donny7833]

Thanks for all the responses!

Those of you that are having good results with acrylic, how did you test adhesion? Cross hatch with tape test, thumb nail, etc.

Thanks, Donny

 

[sjm]

Thumb nail, here ... over time you learn to trust your instinct.

 

[SignManiac]

I tested a print on the acrylic and it adheres really well on the fb950.

 

[Zoomer55]

Donny,
I was at the ISA show and we had the first US showing of the SwissQprint Oryx UV flatbed printer. We printed on Acrylic all day long. I first asked if it was Acrylic because the adhesion was so good. I was shown the label before removing the liner to print and it was Acrylic.

The SwissQprint Product Marketing Mgr. informed me they had their ink made to promote better adhesion on tougher substrates like Acrylic with additional preparation of the surface. The Oryx enjoyed a great 1st year in Europe in 2009 with 50 printers sold. Much of the success was at the expense of the Oce GT3XX/Fuji Acuity partially because of the good adhesion to Acrylic.

The photos attached are of an adhesion cross-hatch test I did on a sample from the show. I'd post it here but can't figure out how. The photo shows the tape and the cross-cut on the back of the print, which had a white flood coat on it also. There is also a close up of the front of the print and one of the overall print itself. I tested it in the darkest area on the print that would have the heaviest ink saturation, which is the most problematic in my experience.

Where are you in WI? I am in MSP and work for WP Digital managing the Western Region for them. WP Digital is a Swiss manufacturer of the Virtu UV flatbeds and we also distribute the Swiss made Oryx printers in the US. The Oryx is slightly more than the $150K you have budgeted but not that much more. You get what you pay for and the Oryx is worth it.

The proof will be in a sample, send me a file and I'll get it done. I look forward to hearing from you,
Bill Grambsch
WP Digital / SwissQprint
201-675-3334

 

[digimon81]

We've got an Gerber Solar Ion, Adhesion to acrylic is horrible. White flood will not stick to the the UV ink ither. Anybody know a good white ink that will adhere to InkJet UV ink? We mask it, so it can be laser cut and when you pull the masking off it pulls the ink off as well

 

[sign_student]

+1

We own a QS3200, adhesion to acrylic is not an issue. When you couple that with the white ink capability that the machine offers it opens a number of new markets for you.

We have printed on virtually everything from ceramic tiles, to glass to formica laminates etc etc quite successfully. Be prepared however as there is a learning curve and finding the right recipe for each substrate will take sometime.

Polycarb for us does pose a problem, specifically in roll form and at 10pt which we must run a specific project with a white ink flood overprint. In order to run this project we have to set the UV lamps at a lower setting (or the polycarb begins to melt) which does leave the inks some what tacky. We work around this by applying a 1.5mil PSA Laminate and everyone is happy.

+1 to this - We use a QS3200 as well and do lots of prints on Acrylic without any problems to date. They look incredible and the adhesion is fantastic.

We also did have a problem printing on a flat sheet of polycarb with white flood coat. A small piece, about the 1/8 the size of a penny chipped off but I am convinced that this was due to the heads jumping... Our main issue was that the ink seemed tacky - We never got to the bottom of it because the print never went out to client and we've been too busy since.

Good luck with your decision

 

[Mspec]

You have to be mindful of what your "acrylic" is made of, UV inks in general should all perform well on Poly Carb, Poly Propylene ( PP ), Acrylic, Lexan. However there are probematic materials that look similar to acrylic such as Poly Ethyelne ( PE or HDPE ) and other coatings that are good for outdoor durability, but bad for UV ink adhesion. If you have poor adhesion on a particular CoroPlast, try another flavor of it. There are dozens of coro look-a-likes and the ones that work the best are fluted polypropylene ( PP ) while others have various amounts of HDPE blended in to make them less likely to crack, make them cheaper to produce, etc. Higher amounts of HDPE mean less adhesion.

Another coating to watch our for is PVDF ( polyvinyndiflorinate ) this is very common on DiBond-like aluminum panels. PVDF is what they make Teflon out of, it will make your panel last for a long time in the elements, but your UV printing will scratch off pretty easily. In some cases you will be better off putting an overlaminate on these materials, ( and leave a small white border so you can encapsulate the prints, or the lam will pull the whole print off if it gets lifted ) There are UV ink adhesion promoters on the market, but they are made for specific applications ( like one for glass, one for PE, etc. )

 

[jdigital]

you may want to try Sericols' adhesion promoters. we use the acrylic one and it holds the ink very well. You wipe it on, let it dry for 10 min. or so, then print. We have Inca flatbeds with Uvijet EI inks and great success with these products.

 

[ellsmako]

It works better but the odor is really something

 

[johnnysigns]

We're running HyFlex Polymeric ink in our Tempo and from the initial tests it's vastly better than the OEM ink. We do a lot of heat bending and routed coro boxes and so far this stuff seems to turn corners very well.

 

[Wowee18]

We run an Oce 350GT and print to acrylic with a promoter with no problems. You do need to run white coverage over any promoter or the colors can be altered. We run the 256 ink set which is more flexible than Oce's 255. We've printed on acrylic, lexan, laminates, painted substrates, aluminum, PVC, etc without issue. Even printed subsurface with backspray paint. There seems to be a solution for any substrate we've ever wanted to print on.

 

[wrapmyride]

i've received some samples from a rastek h650 on Forex and adhesion looked good,

 

[NolaSignGuy]

I run a qs3200 and a qs2000 and have used the recommended adhesion promoter from vutek and it works perfectly each time. It is pretty damn expensive, but the quality makes the it worthwhile. Also printing directly to the substrate eliminates so much labor.

 

[miker]

just curious, what is the recommended Vutek Adhesion Promoter?