Weird banding... 'ever got something like this?

[Patentagosse]

I'm trying to print 3 backglass for 3 different customers but the one in the middle, whatever I'm trying, is always full of major bandings. The 2 other files are OK. I first thought the banding was caused by the tension from the roll (back) and/or the take-up (front) but after giving some loose and turning off the take-up, it's still a mess.

I'm out of solutions...

 

[LFC911]

does the banding go the other direction when you rotate the file 90*?

 

[Patentagosse]

Problem is... the image is 65" long but the material / printer is only 54" so even if it solves the issue, I won't be able to print it vertical.

 

[Patentagosse]

Head is printing correctly (test is 100% perfect) and the profile is 720x720 ('also tried 540x720). Turning off the take-up has improved the result by 50% the the remaining 50% is still unacceptable.

 

[P Wagner]

This is referred to as 'white banding'. It almost always appears in solids or gradients, and can be specific to some colors and not others. We have seen this problem on multiple printer and ink brands (Roland, Mutoh, Mimaki), different types of media (PVC banner, adhesive vinyl, photobase paper) and different RIPs. The only constant is that the printheads in all of the machines are made by Epson (DX4, DX5, DX6)

All i can recommend is to print this file at a higher pass count (like a W-pass 10-pass mode if you're using Versaworks) at the resolution you choose. I believe that the problem will still be present, but will be better hidden by the higher pass count.

 

[Patentagosse]

(W-pass 10-pass mode if you're using Versaworks)

'Never heard of that setting

'Will also try to convert the whole design to raster, in case it may helps...

 

[a77]

Is the media buckling a bit right under the printhead? I've had a problem where I would get faint lines of horizontal banding every couple inches or so.. I believe it's caused by the media repeatedly going a bit high, then a bit low.

 

[P Wagner]

(W-pass 10-pass mode if you're using Versaworks)

'Never heard of that setting

'Will also try to convert the whole design to raster, in case it may helps...

Look in the Media Explorer under the media menu in Versaworks. Choose the media in the left pane and look for 'W +Pass' in the right side. See attached screen capture.

 

[nashvillesigns]

banding

check to make sure the vacuum pressure holding down the material is good. it looks like the material is coming off the table and the print is mislaying the bands in the middle...
run a print test and make sure the lines are firing on top of each other....

 

[Maxphobia]

I've found its a flaw in the material. Try loading a different roll and printing it, see if that fixes it. If so contact your supplier and report the defect they should be able to refund you for the cost of the material. Though it could also be your heat settings to warm typically.

 

[Baz]

Is it me or do you not have any pinch rollers holding down your material in the center?

That could be your problem right there. Material is not held down consistently accross causing it to lift in the center.

 

[gregwallace]

You might try swapping the center file with one of the outside files.

 

[Patentagosse]

You might try swapping the center file with one of the outside files.

That's what I'm trying at the moment... I'm crossing my fingers

 

[Patentagosse]

Is it me or do you not have any pinch rollers holding down your material in the center?

That could be your problem right there. Material is not held down consistently accross causing it to lift in the center.

'Never used center pinch rollers to avoid any marking or contaminants to touch the surface. 'Never had a single issue related to that before. I'm looking very very closely in the middle of the print area, the vinyl is moving forward freely, smoothly, w/o a glitch.

I've swapped the centre image to the edge, turned it 180° to had the gradient light side on edge - dark side next to the solid black background of the other file. After 1/3 of the print done, it's perfect. 'Hope it will stand that way 'til the end...

 

[Patentagosse]

50% done... Woot! Woot!

 

[gregwallace]

Good. I have this problem from time to time and have to rotate my files accordingly.

 

[Patentagosse]

Damn it! everything went smoothly but 10" before the end, it did it again. The customer will have to live with it as I've already ruined too much material & time on this.

 

[P Wagner]

The potential causes of this problem are several:

a) Dirty linear encoder/ sensor
b) dirty rotary paper feed disk/ sensor
c) Leak in ink train
d) Failing printhead(s)

If you search 'ink dropout' you will see thread after thread dedicated to this issue over the years, with various Roland, Mutoh, Mimaki machines. People think that they have solved the issue, only to have it return shortly thereafter. The problem with random issues like this is that they are nor repeatable on demand, and we are never sure if they are truly solved, or merely waiting for the next occurrence to strike.

The only proven method to mitigate this is to print at higher pass counts, which slows throughput.

 

[brush1]

I have 2 SP 540V.
One is doing this from time to time.
For almost 9 years I didn't find why.

 

[klingsdesigns]

My vp 540 randomly does this. When i print on canvas i notice it a lot.