reviving print heads on UV flatbed

[Cranniga1]

Hello I am running an Arizona Oce 360 XT that has been giving me some issues with my test prints. I am getting clogged nozzles on both of my white heads routinely as well as one of my yellows. I know there are a ton of tricks for reviving solvent print heads, but haven't found anything on flat beds. I inherited this machine after 4 years of it being used and maintained by 3 other people, so I am not 100% on the maintenance quality of the past. I do know one of the white heads was changed last year, and the past 8 months I have been behind the wheel I have been very consistent in my cleaning of the machine. Any help on this would be appreciated.

 

[DerbyCitySignGuy]

Hello I am running an Arizona Oce 360 XT that has been giving me some issues with my test prints. I am getting clogged nozzles on both of my white heads routinely as well as one of my yellows. I know there are a ton of tricks for reviving solvent print heads, but haven't found anything on flat beds. I inherited this machine after 4 years of it being used and maintained by 3 other people, so I am not 100% on the maintenance quality of the past. I do know one of the white heads was changed last year, and the past 8 months I have been behind the wheel I have been very consistent in my cleaning of the machine. Any help on this would be appreciated.

Are the nozzles clogged or are they completely out?

There are a few general things you can try that should apply to just about any flatbed printer. Create a "capping station" and soak the heads in cleaning solution. Take a piece of Gatorfoam or some other rigid material, wrap in plastic wrap, then soak some lint free cloths poly wipes in cleaning solution and let the heads sit on that overnight. If it's a constant issue, you might want to do this any time you're down for an extended period of time, like over the weekends.

You can also try to manually flush the heads with cleaning solution. Get a syringe and connectors and just push it through the head. Just make sure you're real careful and you do it very slowly so you don't damage the head. Flushing from the subtank can also help.

I'm not super familiar with Oce printers, but you should be able to use any of these methods.

 

[Cranniga1]

Thanks, I did a soak with lint free cloths for about an hour it helped a little but but I think I may need to do it over night like you said. I am pretty sure they are clogged as opposed to out. I would post a picture but the yellow is so light on the test print I dont think it would be visible.

 

[SignMeUpGraphics]

We have this same issue with our 360, and I believe the behaviour is "normal" and you just need to persist with it.
The white inks are very dense and contain metal particles I believe. The section of the heads that constantly block are the parts just below where the ink feed tube goes into the top of the head.
This causes the heavier particles to settle in that area and block that 1/3" of nozzles.

We alternate between both Océ flush and 99.9% isopropyl alcohol to clean our heads.
It can take 30 mins to get them firing properly again if the printer is left more than 1-2 days (although the white heads will still begin to clog much earlier than that).
We can print white all day long, then leave the machine alone for 30 mins and some white nozzles will begin to stop firing. A quick purge usually gets them back in line.

CMYK causes us no such issues, and will clean first time (99% of the time) and won't clog up even after days of non-printing.

 

[DerbyCitySignGuy]

All the inks contain metal to some degree, but white ink contains more than the others. I believe it's titanium dioxide that's used in most (all?) white inks. The drawback is that it causes lots of clogging in print heads, which is why most printers have recirculation systems for white.

If you're having a lot of problems, you can also gently agitate your white ink by hand every couple of hours. Your mileage may vary, but if you're not using white every day it can't hurt.

 

[Morkel]

We have a 480XT which is about 2 years old now. The white starts to block up after about 10 minutes (if the ink heater has turned itself off, time to re-clean) and the yellow is not much better. The white one is normal (though ours degrades quite fast), but the yellow one is because of the print head - it loses roughly it's middle third nozzles after about 15 - 20 minutes, and then most of the rest by half an hour. A regular purge & vacuum gets it back immediately, but it's just something we live with and not uncommon when they start to age. The reason we know it's not air in the lines or anything like that is because it used to be the Magenta doing it - we swapped the head with the yellow and then the yellow did it. It was a lot easier than pulling apart the entire ink line and looking for leaks etc, which in the end we wouldn't have found anyway! The only way to fix it is a new head.

One thing to mention. Before this we had the 350GT. It was an absolute no-no to apply flush anywhere on the heads (you had to clean it with a dry stick, regularly enough for the ink to not dry). Apparently the flush would easily seep up and destroy the electronics, so the nozzles wouldn't fire. We lost a couple of heads before Oce figured out what was going on, we weren't the only ones it happened to and thankfully it was all fixed under warranty. Now I KNOW the XT models have totally different heads, and I KNOW we've been told that you can flush these ones. But I'm still hesitant, especially to expose them for a full 24 hours.

Have you been shown how to do a long purge? I assume you know you can turn off the valves at the top to turn off any inks that you don't need to purge. If you leave the valves open, then close them the moment the ink starts coming out, it continues to purge until the entire reservoir is empty (probably about 1 minute). If you open the valve again it'll immediately stop, so you don't need to purge the full reservoir, but even doing this for 15-20 seconds pushes a LOT of ink through and can unblock stubborn nozzles quite well. If you wear gloves and don't mind making a mess, while it's purging is a good time to get a stick with flush on it and really wipe the underside of the heads good - the fact that it's continuing to purge means any flush gets, um, flushed away with the ink and definitely will not get in to any electronic areas. It's probably what I'd do before I go drowning the heads.