H1625 LED & Coroplast

[AGCharlotte]

Anyone have issues with ink adhesion printing to coroplast with the H1625? The ink seems tacky initially after printing and heavy solids are relatively easy to scratch. I've seen people mention adhesion promoters and what not in other threads, but I'm not sure that's the proper route and 90% of the time I've tried to clean a board with isopropyl, it leaves "wipe" marks that show when I print.

 

[Glavin_ID]

I have a buddy who has an EFI LED machine and we have had the same problem in the past. He did all my flatbed printing for me for years and we printed a ton of coroplast that had black background with white letters. It never seemed like the black ink was cured (tacky) and they always scratched real easily. He was never able to fully solve the problem but now that we have our own flatbed, the research I have found says that either Matra Plast or Inteplast corrugated plastic work best. Something about the chemical mixture from what I have read. I couldn't find anyone who sold Matra Plast locally but one of our suppliers does sell the Inteplast so that's what we went with. We haven't had any issues yet but we just got our machine setup recently. As for the "wipe marks", are you rubbing until the alcohol is completely evaporated or just wiping a little bit then letting it air dry? Our tech made a big deal about making sure we wiped until the alcohol was all gone and not let the streaks air dry.

 

[AGCharlotte]

It's definitely the air dry, I know it's better if I use a 2nd rag to dry wipe after the alcohol. It's still a bit annoying trying to clean down a large piece and dry wipe it before it air dries.

 

[Glavin_ID]

The other thing our tech mentioned was making sure the alcohol isn't watered down any more than 10%. The more water, the harder it is to get dry.

 

[Superior_Adam]

I had a EFI 1625 but recently upgraded to the EFI 16H and have the EFI 24F. The 3M inks wil initially be tackey but will go away after about a day or so. I have had zero adhesion issues but I only print on Matra Plast coro. As far as leaving streaks you have to wipe and not let air dry. Stoner has a 99.9% pure that we use. Evaporates real quick. I spray on a paper towel then wipe down. Never have streak marks.