White dots on media?! vs-640 Help pls!

[XL_poster]

Hi guys!

I have some problem, with print quality on media like vinyl and bb paper.
I've tried 2 different manufacturer's media (oracal orajet, Avery dennison mpi300). The rolls are brand new and fresh.

The problem is that, there is white dots on the media what is really annoying when print full colors.Pics attached.

Testrpint is 100%, no overspray (static) signs.

I run on alternative ink, print surface and dryer is on 40 Celsius.
the spots not shown on 200 gr solvent paper, or other media.

The ink distributor supsect water in ink lines....thats crazy?!
Avg humidity is about 35-45 RH%

Ive checked the headcarrige line which has its own "lubrication box" but is was clean and ok. Oil can not spray from this box
any suggestions? What should I do or check?

 

[Jester1167]

Typically the first foot and a half of media are considered contaminated every time you load the roll.

 

[XL_poster]

It is also present on 2m or longer media, without reloading or touching the roll.

 

[Ragnabrok]

what ink config is your VS running? does it have white or cleaning ink running?

That looks like media contamination, but shouldn't be across 2 different brands. How's the dust in your print area? unrolling vinyl generates a good amount of static, and will pull anything floating around onto the surface.

An easy test is to use a swiffer duster after loading and see if the dots go away.

 

[Triggerhappy]

it`s not the material

i`ve seen this many times, unfortunately still don`t know what the cause is, but i`m sure it`s something environmental. Has to do with humidity, temperature.
Changed windows recently?

 

[XL_poster]

the area is almost dustfree.
Yes it has 2 cleaning carts instead of white and metallic ( refillable by drained ink )
The problem not present in clean c/M/Y/K colors, so if i print only black or magenta or so, its ok.
As I try to print mixed color (eg brown 40%70%100%50% cmyk) dots become.

 

[XL_poster]

SOLVED!

Problem SOLVED!

I changed the whole ink set to other manufacturers liquid... now run on marabu ink :Big Laugh

 

[ams]

first of all, stop using 3rd party inks. Second, every new roll you should cut off the first 3 feet, it's no good. Third, if you manually cleaned the print heads, it could be dripping ink happened to me a couple of times, too much solution.

 

[OzarkDigital]

We've been fighting the same "white zit" thing for months. If you look at them under a loupe, there's a white spec (missing ink) in the middle and a dark round "halo" around the sit that's the same color as the background. This happens when a piece of dust or debris is "hit" by the ink jet and the ink just "splatters off" the dust particle to the area around it, forming that white hole and a dark halo.

In addition to throwing away the first 3 feet of a new roll, we cured our problem a very strange way: WE LISTENED TO THE REALLY SMART LADIES IN OUR SHOP!

They said, "just hang a bunch of Swiffer pads off the back of the printer so they "drag" all across the media before it goes into the printer." SOLVED! We haven't had a white zit in months! Unconventional but they work! We replace all the pads monthly (no jokes here please fellas!)

We bought 14 Swiffer pads. Taped them on the back so they're barely touching the media all the way across the back (they're in the way when we load the media, but we get used to it, just raise the Swiffer pads and put the media in.)

Hope this helps ?!?!? Dennis