VJ 1614E strange printing problem

[FaneDuru]

Hi,

Since some days we cannot print in good quality on plastic media (vinyl and backlit).
In the attached photo you can see black ink exactly on the direction/path of machine rollers. Those rolls are perfectly cleaned. It looks to me like static. I thought that the rolls do not freely move in their location and I cleaned them on the sides too. I thought that maybe when the machine pulls the material the rolls do not follow it perfectly and a small friction between media and rolls can send electrostatic charge to the material. If it is only locally charged it may produce that effect. The picture was done after all that cleaning. Before that, it was worse but I do not have the samples any more...
I checked the earth connection of the machine and no problems from that point of view. The printing head is also well connected to earth. What I found, but it cannot be an issue, the working table of the VJ machine is coated with some very resistant insulating material...
It is good to mention that it is not a rip or machine printing head problem. The same file is perfectly printed on paper!


Did somebody else face such a phenomena?
What do you suggest to tray in order to solve the problem?


It looks to me clear enough that it is a static issue, but I do not know how it appeared and what to do in order to solve it. Only on the rollers path... Maybe the plastic material covering the rollers, because of aging became harder and may slip. But if this would be the reason it is impossible that only here such a thing to happen. Did somebody else face something similar?
I thought of air humidity but it would not act only on the rollers path. It reins all the time but it is also hot. Because of air conditioning the air is a little dryer the usually but I cannot imagine how that would affect in that way the printing...

Maybe is good to say that the effect is obvious when printing black on white background. For a picture even if with high resolution it looks that no such obvious effect appears... At least/mayby thay cannot be observed.

Thanks in advance!

P.S. Can anybody send me (PM) a service manual for that type of machine (VJ-1614). Any help on the issue will be much appreciated...

 

[GaSouthpaw]

We used to get this a lot on static cling material (VJ1624, though), but not so much on other media. I found that cleaning the rollers helps briefly, but- depending on the age of the machine- you may just need to replace them. Bell & Howell is where the ones for the 1624 come from. They're something like $15 each, so it cost $350 or so to replace ours. A heck of a lot better than wasting material and the associated aggravation.

 

[FaneDuru]

We used to get this a lot on static cling material (VJ1624, though), but not so much on other media. I found that cleaning the rollers helps briefly, but- depending on the age of the machine- you may just need to replace them. Bell & Howell is where the ones for the 1624 come from. They're something like $15 each, so it cost $350 or so to replace ours. A heck of a lot better than wasting material and the associated aggravation.

Firstly, thanks for your help!
Machine is 3 years old. It worked all the time in a conditioned space, so I still hope that not the rollers are the problem. I just wanted to know if somebody else faced something similar and how they used to solve it... I would not change the rollers based only on my supposition even if the imagined mechanism of static charging sounds logic. Cleaning the rollers with solvent may soft their surface and this maybe helps in order to avoid the slip. I tried to heat them with hot air and it looks that helps a little.
I am thinking at using one of that elastic anti static devices... It is just a small space between the rollers and printing had. Did anybody else tried that?
I also observed that the elastic side of some rollers exceedes the inner metallic part on both sides and that may create supplementary friction on the lateral. Maybe they have been elongated during the last often cleaning with solvent.

How old was your machine before rollers replacement? After replacement everything from that point of view was OK?

Did anybody else faced anything similar and the single solution was rollers replacement?

 

[GaSouthpaw]

Firstly, thanks for your help!
Machine is 3 years old. It worked all the time in a conditioned space, so I still hope that not the rollers are the problem. I just wanted to know if somebody else faced something similar and how they used to solve it... I would not change the rollers based only on my supposition even if the imagined mechanism of static charging sounds logic. Cleaning the rollers with solvent may soft their surface and this maybe helps in order to avoid the slip. I tried to heat them with hot air and it looks that helps a little.
I am thinking at using one of that elastic anti static devices... It is just a small space between the rollers and printing had. Did anybody else tried that?
I also observed that the elastic side of some rollers exceedes the inner metallic part on both sides and that may create supplementary friction on the lateral. Maybe they have been elongated during the last often cleaning with solvent.

How old was your machine before rollers replacement? After replacement everything from that point of view was OK?

Did anybody else faced anything similar and the single solution was rollers replacement?

Ours is in a closed room, too- but the rollers do wear out from use, not just from getting dirty.
Definitely do not use solvent to clean them- it won't soften them, it will destroy them.
The most effective method was to pop the rollers out and soak them in isopropyl alcohol overnight or over a weekend (this was suggested to us by a Mutoh tech). You'll be surprised by how "gunk" much comes off. Perhaps trying that first will solve your problem. If it does, you're luckier than we were!
Our printer predates me here by about six months (an abused six months of being operated by people who didn't really know what they were doing), so it's about 3 1/2 years old. The rollers just wear out from use- no matter how much you baby them. I'm hoping to get a better life out of the new ones, since I have a better idea what to do with them for maintenance. Replacement of the rollers eliminated those marks on our prints.
Good luck!

 

[x2chris7x]

+1 to replace rollers... Does this happen all the way across the media? We get some roller marks in our prints from time to time, but they are less noticeable to the far left of the machine b/c most printing happens from mid to right of the machine. Is your print quality any better when printing to the far left as opposed to the far right?

 

[GaSouthpaw]

+1 to replace rollers... Does this happen all the way across the media? We get some roller marks in our prints from time to time, but they are less noticeable to the far left of the machine b/c most printing happens from mid to right of the machine. Is your print quality any better when printing to the far left as opposed to the far right?

You're right- I forgot that part. Another temp "work around" is to remove the offenders, or swap them out with the ones that rarely see use.

 

[tgrinds]

Try swapping the rollers in the problematic area with ones at the very end and see if the quality changes. If so, then it's the rollers. Good luck.

 

[FaneDuru]

Ours is in a closed room, too- but the rollers do wear out from use, not just from getting dirty.
Definitely do not use solvent to clean them- it won't soften them, it will destroy them.
The most effective method was to pop the rollers out and soak them in isopropyl alcohol overnight or over a weekend (this was suggested to us by a Mutoh tech). You'll be surprised by how "gunk" much comes off. Perhaps trying that first will solve your problem. If it does, you're luckier than we were!
Our printer predates me here by about six months (an abused six months of being operated by people who didn't really know what they were doing), so it's about 3 1/2 years old. The rollers just wear out from use- no matter how much you baby them. I'm hoping to get a better life out of the new ones, since I have a better idea what to do with them for maintenance. Replacement of the rollers eliminated those marks on our prints.
Good luck!

We firstly cleaned them twice using the cleaning liquid of the machine (WO 131). When I said 'solvent' I was refering (probably wrong) at isopropyl alcohol. Except the two first cleaning, for about 6 to 7 months we cleaned them in place just wiping with a piece of cloth soaked in isopropyl alcohol. I used to think that they are dirty and this should be the reason of the problem. When I started thinking at that mechanism of static charging by friction because of possible braked rollers I took them out and cleaned their laterals, too. Also using isopropyl alcohol. It improved a little the situation but did not solve it. I am afraid now that I 'descovered' the mechanism a little to late...

I will also try to soak them in isopropyl alcohol for this weekend and I will let you know what happen.

 

[FaneDuru]

Try swapping the rollers in the problematic area with ones at the very end and see if the quality changes. If so, then it's the rollers. Good luck.

I will also do that. But I was very 'conscientious' and I cleaned and unused ones every time. If this 'treatment' has worn them equally maybe the result will not be the expected one. But what will cost me to give it a try? Thanks for the tip!

I still hope that their behavior doesn't come because of their strengthening because of aging (in case of wrong material used, or wrong maintenance...).

 

[GAC05]

We used to get this a lot on static cling material (VJ1624, though), but not so much on other media. I found that cleaning the rollers helps briefly, but- depending on the age of the machine- you may just need to replace them. Bell & Howell is where the ones for the 1624 come from. They're something like $15 each, so it cost $350 or so to replace ours. A heck of a lot better than wasting material and the associated aggravation.

Do you have a part number or link to the Bell & Howell page for these?
I did a search but couldn't find anything Mutoh specific.

wayne k
guam usa

 

[MagnetStew]

Do you have a part number or link to the Bell & Howell page for these?
I did a search but couldn't find anything Mutoh specific.

wayne k
guam usa

I have found that the best cleaner for the rollers is lighter fluid. You don't have to apply much friction to get the "gunk" off and it doesn't break them down. We have this problem from time to time and cleaning the rollers with lighter fluid fixes it right up.

 

[GaSouthpaw]

Do you have a part number or link to the Bell & Howell page for these?
I did a search but couldn't find anything Mutoh specific.

wayne k
guam usa

I can't track it down right now, but we had to call them to get them. They weren't listed anywhere online that I could find, either.
(800) 792-4782

 

[FaneDuru]

I have found that the best cleaner for the rollers is lighter fluid. You don't have to apply much friction to get the "gunk" off and it doesn't break them down. We have this problem from time to time and cleaning the rollers with lighter fluid fixes it right up.

When you say 'lighter fluid' what do you mean? "Volatile liquid hydrocarbon mixture used in wick type lighters" or "aliphatic petroleum solvent used in lighting charcoal in a barbecue grill" (wiki...)?
What is it in fact?
Maybe it is able to soften the material and no friction occur for a specific period of time. Now I am pretty sure that the problem is not the dirt, it is static charge because of friction on plastic media if roler surface is hard...

 

[GaSouthpaw]

When you say 'lighter fluid' what do you mean? "Volatile liquid hydrocarbon mixture used in wick type lighters" or "aliphatic petroleum solvent used in lighting charcoal in a barbecue grill" (wiki...)?
What is it in fact?
Maybe it is able to soften the material and no friction occur for a specific period of time. Now I am pretty sure that the problem is not the dirt, it is static charge because of friction on plastic media if roler surface is hard...

In my pre-sign guy life, I worked at a waterjet company that made various parts from rubbers, plastics and urethane. If your problem is that the urethane on the roller (the cover) is hardening, it's because it's old and needs to be replaced. It doesn't matter what you think the hardened roller is causing (static), the root of the problem remains the urethane. You can try every other fix you want, may one of them will work- but it'll only be temporary and you're going to end up having to replace the rollers.
One last thing- don't use the head cleaning solvent on the rollers, either. You'll just damage them more. The rollers aren't actually supposed to be soft- they're supposed to be firm (not hard).

 

[GAC05]

I can't track it down right now, but we had to call them to get them. They weren't listed anywhere online that I could find, either.
(800) 792-4782

Thank you.

wayne k
guam usa

 

[MagnetStew]

When you say 'lighter fluid' what do you mean? "Volatile liquid hydrocarbon mixture used in wick type lighters" or "aliphatic petroleum solvent used in lighting charcoal in a barbecue grill" (wiki...)?
What is it in fact?
Maybe it is able to soften the material and no friction occur for a specific period of time. Now I am pretty sure that the problem is not the dirt, it is static charge because of friction on plastic media if roler surface is hard...

Charcoal lighter fluid.....Kingsford to be exact. We use the odorless but I dont think it matters.

 

[FaneDuru]

In my pre-sign guy life, I worked at a waterjet company that made various parts from rubbers, plastics and urethane. If your problem is that the urethane on the roller (the cover) is hardening, it's because it's old and needs to be replaced. It doesn't matter what you think the hardened roller is causing (static), the root of the problem remains the urethane. You can try every other fix you want, may one of them will work- but it'll only be temporary and you're going to end up having to replace the rollers.
One last thing- don't use the head cleaning solvent on the rollers, either. You'll just damage them more. The rollers aren't actually supposed to be soft- they're supposed to be firm (not hard).

What you say is correct!
I have this (maybe fix) idea that static is the problem and mechanism of charging should be the friction because of rollers slip when material is pulled. Rollers slip because of their hardener surface then before. But I cannot be sure... Maybe it is something else or something else to be added at that behaviour. That's why I try to do whatever looks to help me in order to make a good diagnosis of the problem. Seeing my uploaded picture can you be sure that my supposition is 100% correct?
If one of those tricks works even for short period I can know for sure that rollers aging is the problem. The strange behaviour appears only on some materials and is completely absent in paper printing. Maybe the material is so wrong in terms of charging and rollers change may not solve the problem...

For instance when this phenomenon appeared first time we have been advised by our service provider to work with the machine handle at the middle position. To less press the material. But it looks that is should be exactly opposite if my 'theory' is confirmed...

 

[FaneDuru]

Charcoal lighter fluid.....Kingsford to be exact. We use the odorless but I dont think it matters.

Thanks!
I will try to find something similar and give it a try.

 

[Solventinkjet]

We stock the OEM Mutoh rollers for $11 each. Here is a link if you need to order some: Mutoh Pinch Rollers

 

[FaneDuru]

I kept the rollers in isopropyl alcohol for weekend.
I printed a piece of vinyl ant it was perfect.
I printed on that new backlit material and it looked a little better but still wrong. I found a piece of previously used backlit material and printed it. It was perfect... I tried to eliminate static charge putting a wire between rollers and printing area. It was connected to the earth and it was touching the backlit surface. The printing was better but not perfect.
It looks that the material used last time is not so good regarding static charge.
When it is a friction on the machine it is very rapidly static charged.
Cleaning (and maybe softening the rollers surface) I could eliminate the effect for vinyl and one type of backlit. The glossy one was impossible to use in good conditions.
I improvised a kind of discharger and succeeded to improve the printing in this way but not enough. I did that only to have e good diagnosis regarding the reason of that appearance. It looks that supposition of static charge is confirmed. Maybe doing the same thing on the opposite side of the backlit the effect would be stronger. But it is not too much space in order to create such a nice looking industrial device... If the result would be better maybe my enthusiasm would help in finding a solution.

Now, do you know if the machine itself has a device/mechanism in order to static discharge? If yes, how and where does it act? Maybe in my case the mechanism of static charge elimination doesn't work (of course if such a device exists...) at all.