Mimaki JV3 160-SP

[JTpro]

Does anyone know why I'm getting these darker lines on the print (see attached image)? The image is a gradient from a light blue to an off blue. A friend of mine was getting the same result on his value jet 1204. I thought it was his printer, but it did the same / similar when I ran it. The lines coming off his printer where more frequent, where mine are less. It did appear to be showing up between the grip rollers and it only shows up on light colors so far with blues and pinks... I originally thought my light cyan / light magenta head was going bad and it wasn't able to line up when printing light colors.

I think that it has to do with the material being slight raised between the grip rollers therefor making the media slightly closer to the head which results in a concentrated ink making it darker.

Any ideas or thoughts?? Also what vinyl do you use for every day interior full color application?

Thanks for your time
Jeff

 

[MikePro]

what's your test print look like?
do you get banding while printing full fields of color?
also, waves in color due to buckling/warping of media between the rollers COULD be an issue BUT the fact that you have heavy magenta & cyan mixtures in the gradient steps leads me to believe this is result of ink supply/printhead/profile issues.

 

[Samurai_Screwdriver]

Question: Are you running the printer in Bi-directional mode? If so, try switching to Uni-directional and see if that makes the problem go away. My hunch is that the media is buckling up between the pinch rollers and is closer to the Heads in these area - This means that the alignment of the dots between the outward and return pass will be out of whack in this area and is causing the color shift (possibly the print looks a little "grainy" in these areas too.

Try Uni and see what you get.

 

[genericname]

Identify or eliminate raised media as an issue by printing the image rotated 90 degrees. Still the same pattern in the same direction? Yeah, more than likely drop concentration as the media lifts between the rollers. Either your temperature is too high/low, or your vacuum is off or dead.

If the pattern also rotates 90 degrees, more than likely resolution and profile are you culprits. I've never seen stepping that bad in gradients though, so unless you're doing something drastically wrong, I'd bet that's not the issue.

 

[particleman]

Is the media tight on the roll and/or are you using the take up? This sort of horizontal banding sometimes happens because of the tension in front of or behind the media. The media will pull off in clumps making the feed comp vary. To rule it out, load the material androll out some of the media from the back side so there is no tension on it. Do the same in front by not attaching the take up and see if the problem still happens.

 

[JTpro]

I should have added:
This was run on 8 pass Uni directional slow speed, head set to low. I've tried various settings 16 pass uni & bi, fast / slow etc... all with the same result.

I did do one with rotating it 90 degrees and I got the same result.

I'm not sure if my vacuum is on or off or broken now that I read that comment. i will search through the LCD set up and see it is turned off. I have to agree with reading all the responses that it is in fact the material buckling between the pinch rollers. I'll run another sample in the morning or late this evening with no heat all after the heaters have completely cooled off to see if it may be a heat issue.

This doesn't show in solid colors or even "medium" colors it's only apparent in the light shades.

 

[gabagoo]

Could it be too much heat?

 

[Morph1]

I also think it maybe too much heat or it may be too humid.... set the heaters on 29 x 29 just before you print raise the rollers and straighten the material and lock them back on , see if that helps... What rip is that coming from ??? also I wanted to add that I have had similar unresolved issues with the prime cast materials , funny enough when I bought the cheapest calendered vinyl it printed perfectly, If you use Flexi try changing the Dither Type from FMXpress to Kfdiffusion the rip will take longer but this usually gives a better gradient blend end result....Let me know if that helped any...cheers !