-
White dots on the printed materials
Hello everybody. Please give any ideas about our problem. We have
VP540, with Bordeux inks.
From time to time some white dots appear on the printed materials, and
in one moment they disappear. We can’t understand why it is happening.
First when this appeared we considered that the material is old or
not good for printing.
And we tested 10-12 other materials (Orafol 641, OrientFlex, Grafityp)
vinyls, banner, translucent…. We had the same result on all of them.
We managed to close the circle around the problem when we printed a
table of the CMYK from zero to one hundred % with step of 10%. The dots
appeared only in the square with 90-100% fillment. We tried everything
we could think about. We raised the humidity in the room, lower the humidity, cleaned the room, cleaned the room, made a maintenance cleaning, several normal cleanings, several test prints (it’s OK), put a ground cable (don’t know how effective it is), we changed the temperature of the room and the print, we cleaned the refills,
dried them, and poured fresh inks….we tried a lot of things.
Please if you have any ideas I’ll be grateful to hear them.
Thank you in advancep.s. Here are some pictures.
-
5 Replies
-
dust spots… but u easily see them on the roll.
New rolls suffers from the 1st meter of material with dust/dirt.
Also storing the rolls stood on the ground can attract dust to one side of the roll because of carpet.
Since we killed the carpet and laminated and put printer in its own room, 90% of dust and nozzle out problems have gone. Basically consider the price of a print head, then two print heads and a floor-fitter.
Static can cause spots but I dont think this is your case.
Hope that helps.
Dave
-
as Dave said, dust spots , espically as you say it only happens with 90 – 100% coverage, the ink pools around the dust and causes the spots, on lesser coverage the isn’t as much ink to pool so it doesn’t happen
Ian
-
10x for the replies, I’ll try to think for a way to get rid of the dust. But from today I have new information. When we started the print again, i paused the heads on every pass. The head returns, caps are rising, 1-2 seconds, and unpause it. The print was perfect, different materials. Also I forgot to mention that we usually print in Uni-direction.
Any other ideas? -
Only a suggestion, but is the profile set so that the ink level being laid down is a little high? The spots could then be caused by bubbles.
-
For those who might be interested, we found the what was the problem.
The main problem was CONDENSE. There was water condensed in the ink cartridges. The condense forms for some period, and the drop falls in the ink (for a month and a half in pur case). It can’t dissolve in the ink and goes on the media. The decision was to pull out the cartridge, remove the ink, and pour cleaning solution. It’s good to the solution through the entire system (some people say it’s good to make these procedure, even if you don’t have problems). When you are sure that there is no trace of the cleaning solution you can pour again the ink. For the next several sq. m. (3-4 sq.m.) you will have these white dots again. But this time this will be from the cleaning solution. It will disappear and everything will be perfect. If you need any help write down to my email.
Log in to reply.