Need Help Scratching/Peeling! Yikes! Lamp power for FB500 coroplast?

[tedbragg]

HP won't give us a straight answer of what to set our lamps to when printing Coro on Express or Indoor Signage Plus. Seems no matter what setting we use (low, med, high) the ink will peel or scratch off easily.

Unless we let them sit for a day to gas out, then they don't perform so bad. But it's maddening. What's the consensus?

 

[flyplainsdrifta]

there is an option to increase lamp power under the options menu on the print screen. have you tried that yet? how old are your bulbs??

 

[tedbragg]

We have new bulbs, cleaned the lenses and shutters 100%. Maybe its the coro? Are there specific brands that do better for UV printing? Our suppliers are a crapshoot, though. Might need a new/better supplier

 

[flyplainsdrifta]

That was my next question haha. what brand are you using? i use matraplast, bought by the skid direct from the factory in Canada. do you have adhesion problems on any other substrate?

 

[Glavin_ID]

Seeing that you have new lamps, have cleaned everything, and have tried all settings, I would guess it is the material. I bought from one supplier for a while and had nothing but problems on our FB700, switched to a new supplier and magically all the problems went away. Sometimes it is the brand (we have had issues with product from China), sometimes it is just old and the corona has faded. I have heard great things about Matraplast, something to do with the chemical composition in their plastic being a little different, but unless you want to/can buy by the skid, it's hard to nail down a supplier who uses only them (or at least it was for me). I just bought one sheet from a few different suppliers, tested them all and found one we liked. I pay for delivery from this place when all the others deliver for free but it's well worth the extra $30 to not have to worry about it. We also had a major issue with our other suppliers material coming in dirty and beat up so that played a roll in us changing too.

 

[flyplainsdrifta]

We have new bulbs, cleaned the lenses and shutters 100%. Maybe its the coro? Are there specific brands that do better for UV printing? Our suppliers are a crapshoot, though. Might need a new/better supplier

if you have a lindenmeyr monroe in your area, they should be stocking the matraplast. they have it in 25 sheet cases and full skids. you could maybe pick up a case and see if you have better luck with it. honestly, sometimes the cases come in better and less banged up than the skids.

 

[greysquirrel]

You need to improve dot gain for adhesion. Lamp power does not do this. Male sure trailing lamp is set to shuttered for whatever mode you are running.
If you want to test the media, clean a portion with 70% alcohol let it dry and re-run. If the ink adheres better in the cleaned area then its the media. You have two options, swap out or pre clean al of your sheets.

 

[ikarasu]

Coro gets treated with a corona. There's cheap Coro and there's special Coro made fornuv printing.

As Coro gets older the plasticizer starts to seep through also, old.coro doesn't print well.


I'd try a different brand Coro and see what your results are.

Also.. how scratch resistant are you looking for? Even with UV lamps a UV print isn't instantly cured. It's cured enough but it takes an addition 24 hours to be fully cured... We were always told.by go not to ship the product for 24 hours.... That being said we always do and never have an issue with scratching. But if you're running the sign against something it'll likely still scratch.