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Hp Latex 360 Prints Grainy

NWDistribution

New Member
So I have ran into an issue with my Latex 360. My company purchased this printer in late July of last year. We bought various size 13oz vinyl substrates (38", 54", & 63") around that same time. Since then I've mainly used the 38" and have re-purchased several rolls. The 54" has been used but still have the initial roll. Two days ago was the first time I've needed to used the 63" roll and I tried printing on it however I get a very grainy image on it. Printing the same image on the 38" and 54" I do not have this issue. What could be causing this problem and what can I do to fix this? Does vinyl substrate expire?
 

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Vinyl banner material does, yes. From what I've read it's the plasticizers coming to the surface of the film and interfering with the ink adhesion. You can clean the material off with isopropyl alcohol before you print, but that's a huge pain and you'll probably have spots that you miss and have bad image quality in those areas..
 

Asuma01

New Member
Xtreme has it right.
Its best not to keep to many extra rolls of banner material on hand. Especially if it is an off size that doesn't get much use.
 

dypinc

New Member
I have to remember that. Have you talked with Lexjet? They are pretty good about replacing or return bad media.
 

AKwrapguy

New Member
So the issue is the banner material that your using. Like Xtreme said about the plasticizers coming to the surface will cause this. HP actually makes a roller that goes on their machines that fixes this issue. It's basically a foam covered bar that pushes the plasticizers back down before it goes through the printer. It might be available for your model.
 

NWDistribution

New Member
So the issue is the banner material that your using. Like Xtreme said about the plasticizers coming to the surface will cause this. HP actually makes a roller that goes on their machines that fixes this issue. It's basically a foam covered bar that pushes the plasticizers back down before it goes through the printer. It might be available for your model.

Unfortunately it looks like this is only on the 560 & 570.
 

Filmpro

New Member
Dear HP-Latex users suffering from „plasticizer migration“,



Grainy prints are a phenomenon that returns again and again on HP-Latex systems. The rumor that this problem is caused by plasticizer migration was started by HP and is still used (see various topics on this forum) but is absolutely not correct.

Would this problem be the result of plasticizer migration, media suffering from it would give poor print results on almost any kind of inkjet printer as this migration would result in a strong reduction of the surface energy of the film. With the problem at hand this is not the case. Media showing this problem on HP-Latex is perfectly printable on Mimaki, Roland and Mutoh printers and even on Ricoh Pro L4160 (Latex). So the cause must be a different one.

It is true however that wiping the surface with alcohol solves the problem as does wiping with a paper towel, cotton cloth, bare hand and the like. Another way to get rid of this problem is moving the media through the printer with standard drying settings at standard print speed, wind back and print on the this way pre-heated media. In all these cases the problem is gone …. for a while. After about an hour (depending on the way of treatment) the problem starts to surface again.



The problem of grainy prints predominantly shows up in polymeric plasticized pressure sensitive vinyls, about 6 months after the PVC-film was adhesive coated. This already indicates that it is very unlikely that we are dealing with plasticizer migration here as this is a process that would take some weeks and would predominantly be present in monomeric plasticized vinyls. Monomeric plasticized media every-now-and-then show this problem too but to a far lesser extend as polymerics. The problem is not restricted to certain media manufacturers; to my knowledge almost every one of them has been confronted with this problem.



Many attempts were taken to clear up the process leading to these grainy prints but unfortunately not one of them lead to solid evidence so far. Known is that the problem relates to some additives used in the PVC-film manufacturing in combination with residual solvents from the adhesive and contact with the backside of the release liner which combination results in a repellent interaction with the ink.



As most of the pressure sensitive media already existed in their current form when HP-Latex was introduced, having the media suppliers solve the problem that is clearly related to the Latex technology seems at least questionable. It would help all HP-Latex users and media suppliers if HP would bring in its development power to research this problem instead of pushing the problem in the direction of the media manufacturers. I am open to any form of cooperation to solve this issue.
 

Joe House

New Member
Would this problem be the result of plasticizer migration, media suffering from it would give poor print results on almost any kind of inkjet printer as this migration would result in a strong reduction of the surface energy of the film. With the problem at hand this is not the case. Media showing this problem on HP-Latex is perfectly printable on Mimaki, Roland and Mutoh printers and even on Ricoh Pro L4160 (Latex). So the cause must be a different one.
2 points here - solvent inks would be less susceptible to an oil based issue (plasticizer) than a water based ink (latex) and I've seen this cause problems on solvent printers as well, however with was on some 2 year old banner material.

It would help all HP-Latex users and media suppliers if HP would bring in its development power to research this problem instead of pushing the problem in the direction of the media manufacturers.
It appears that HP has put it's research power into this and provided a solution on their latest platforms (500 series printers)
 

JHeard

Member
Any updates? I am having almost the exact same issue on my l26500, Onyx 18 is my rip. I'm using a brand new roll of matte vinyl (don't know how long it was in the warehouse) and am about 1/2 through the roll with the problems persisting. This is actually my second roll this is happening on.

Some colors are super grainy, some look like the ink is beading up, have the same "plasticizer" vertical waves in some places. Some spots look fine. Print head alignment and print head health tests look fine, color calibration prints look nearly flawless but then I send a test print and it looks terrible. I'm also having an issue on some solid colors where it almost looks like the ink is "starving" and I'll get splotchy areas where there is almost no ink at all.

I've cleaned the printer, recalibrated in Onyx, changed the substrate advance, switched the profiles, rebuilt profiles, tried adjusting nearly every setting on rip and printer even the service menu tests, all to no avail. I don't completely understand color profiles, but I've tried several canned ones and tried building my own, I've changed heat and vacuum settings, I don't know what to do with the ink limits and linearizations, but trial and error has not improved anything.

If I do 2-3 print head cleanings, print 18-20 pass, color variation correction on, vertical correction on, extra print head cleaning on I *might* get a passable print. At first I thought it might be from not using the printer for a few days, but I have used it a ton in the last week or two and it seems to only get worse.

Any other ideas? Is it for sure the media/plasticizer migration? I've been using the same brand media for about a year and just now getting issues. Also doesn't explain why my color calibration tests don't have this problem, which makes me think it's a profile issue, but I hadn't changed the profile when this started. I've been testing literally all day, any recommendations would be greatly appreciated.
 

eahicks

Magna Cum Laude - School of Hard Knocks
Use to use Ultraflex banner for years on various solvent machines. Once switching to Latex machines, can't use it anymore due to this. NONE of their stuff we get runs right. So we use GSG Starprint or Grimco's Key banner. And like someone mentioned, don't store several rolls in your shop for along period of time, because of some "deal" that comes along. Buy them as needed (one or 2 on hand is ok.)
 

dypinc

New Member
The easiest way to tell if is media/plasticizer migration is to wipe an area down with alcohol and see if it changes how the ink lays down. If it looks good where you wiped it then you will know. So then you can decide if you want to wipe down the roll before you print or trash it. But do try to get another roll from the manufacture/distributer first before trashing the roll.
 
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