White Dots appearing in prints

[MikePro]

After about 100ft of print, my Mimaki JV3 160sp suddenly starts printing white dots in my red fields and will not stop. CustodyWash's, Nozzle Washes, test draws look great, and even did 2 head wash/ink fill cycles and I'm still stumped.

By white dots, i mean in the fields of red i'm printing... it looks like randomly there are shotgun blasts of where ink refused to lay down on the material.
Also paired with this, there seems to be small hair-like particles contaminating my print as well, but unlike the white spots... the red ink still lays over them, creating hundreds of dozens of darkened flecks in the print. At first I assumed dust, and did a full clean of my printer and work area... but I still cannot find the source of this headache.

 

[wildside]

depending on what type of material you are using... it may be the material itself, we have noticed little fibers like that in cheap vinyl in the past, and some "UV" coated materials get splotchy patches and create nightmares

you printer and work area may be fine, your material may not.....

or it could be your printer, but have no idea without visibly seeing what you are talking about.

 

[Letterbox Mike]

It sounds like material contamination to me. Try switching media to see if it persists.

 

[Mike Paul]

Contaminated material will cause fish-eye.
Are the heaters on and on the same setting? Heavy ink load and slow drying can show dust in the print.

 

[Gino]

Welcome from PA.......................................

 

[MikePro]

material contamination wouldn't surprise me, MacTac would be the culprit in this instance. Although this is my 20+'ith roll since putting my trust into the brand and only first time I've seen this error in such frequency.
Throwing on some 3M material in hopes of confirmation.

 

[Printhead]

It could also be your ink coverage that's too high for the type of material you're using. Too much ink will cause fisheye.
Try lowering ink coverage and raising the pre and printing temperature.

 

[MikePro]

thanks for the input thusfar, but i'm still stumped. not especially looking forward to getting a tech out here but I'm going to have to make that call today if I can't figure anything else out.
Changing materials still showing the same issue, and raising the print temp. as well. Ink coverage could be an issue since I have always noticed that during these prints that it looks a bit "liquidier" than other projects, but I still have faith that it is something else since this is now happening after nearly a mile of print from these same files.
granted, i'm using the profile from 3M IJ180C-10 for MacTac JT5828 material (upon recommendation from our supplier) which again, has always worked over the past couple of years.
posting pics for reference:

 

[Letterbox Mike]

To me it still looks like very dirty media. It's hard to tell from the picture but I see what looks to be some dirt or gunk causing some dark spots as well.

 

[MikePro]

the problem, at the moment, has disappeared!!!
thanks to everyone for their input.
I loaded a 3rd roll of new MacTac material since the issue started, and after the first 3 feet of print the white dots were no longer an issue.

my theory, although still not 100% certain, was that maybe I had recieved a contaminated roll(s) which may have transferred to the feed rollers and debunked my original attempts to confirm the soiled roll by changing to different materials.

Still debating how/if I'm going to go about returning these first two contaminated rolls to our supplier... if i can at all (1st one I had burned 60ft, and 20ft on the second... not to mention the ink drainage bottle on my printer housing a couple hundred dollars worth of ink from all my attempts to clean the system during this whole ordeal! (or the 2days worth of work invested...)

 

[Printhead]

Did this happen in red zones only?
It looks like fisheye. I would try lowering the magenta and yellow ink coverage, it certainly couldn't hurt and I'm pretty positive you could have a red as vibrant while being less "liquid", and saving ink in the process.
Otherwise, I printed thousands of roll, many of which were corrupted and the grease or whatever is wrong with corrupted media never jumped on the feed rollers.
Good luck!

 

[tanneji]

Definitely material coating issue ... we get that sporadically in our banner vinyl ... very very aggravating but we but the 30 pack of sharpies and most of the time there is a color in there that will mostly cover it up