Clear Coat over UV Ink

[bagdaddys]

i get my 2'x4' signs printed at a local sign shop. They print direct to the surface using one if their flatbed printers. They use a UV ink...not sure what type/brand. I then take these signs, do some minor finish works and then apply a water based clear coat.

my issue is that on this last run of material the clear coat will not bond to the printed surface. It dries and I can peel it off. This has never happened before.

in the last 48 hours we have been through a process of elimination to narrow the cause down. We discovered that these signs were printed on a different machine that uses a different type of UV ink. We have used 2 types of water based clear and one oil based clear and none will bind to the ink.

ok....so the long term problem is solved....use the ooriginal machine for all future prints!!!!

my immediate problem.....I have 84 signs with this NEW ink and a deadline that will not allow the time needed to reprint the signs. HAS ANYONE EVER COME ACROSS THIS ISSUE AND IS THERE ANY TYPE OF CLEAR COAT I CAN APPLY THAT WILL BOND TO THE SURFACE??????? PLEASE SAVE ME SIGNS 101. This contract will keep me busy for the next 2 years if I can delivery this first order on time and of a high quality.

 

[P8106jr]

Several companies offer solutions

Polymeric out of Kanasa City water based clear coats that will stick to Uv inks

 

[studebaker]

Run them through the laminator....

 

[artbot]

did you figure out the adhesion promoter solution? from your last pm i wasn't sure it was being applied correctly. also, if you could name the actual printer/ink used your signs are printed with that would open up better technical discussion. also, take photos of the peeling, your spray set up, space, environment (humidity), mil thickness, retarders, thinners. there's guys on this forum that have been spraying substrates for decades and have run in to just about every possible issue. we'd just need more data to figure out a solution.

 

[gregwallace]

We use clearshield production clear gloss or semigloss for our uv prints. Its made by marabu. The production series used to say for increased adhesion on difficult substrates but they changed the labeling so it doesn't say it anymore. We originally used it to precoat our coroplast before vutek released an ink that would stick to coroplast. I'm not sure what you're using but they have different grades of uv coatings that might be worth looking into. We also have a cheaper coating we use for billboards. If you use it on coroplast it peels right off.