Roland VG-640 Leaving Pinch Roller Marks

[Sign Pro Salina]

Our Roland VG-640 has starting leaving pinch roller marks in our prints. I've cleaned the rubber wheels with alcohol several times & tried a rag with mild detergent as the manual recommends. I've also adjusted heat settings up and down & off. They are still present with the heat off. It's causing them on both cast and calendared Orajet vinyl, so not just one roll of media. In the past on this machine and our old Roland, the marks were caused by either dirty pinch rollers or a heat setting.

I can not get them eliminated this time. Is it possible that the bar that the pinch rollers connect to has developed too much downward pressure and needs an adjustment? Or is that even possible?

I am stumped as to what else could be causing them, if I've missed anything. It was printing fine & then started causing the marks.

I've attached photos showing the roller marks. Typical heat settings have been, Print 98 degrees & Dryer 110 degrees.

Any ideas or thoughts on why this is happening are appreciated.

1st photo is 86 degrees with clean rollers, 2nd photo is 112 degrees with clean rollers and the 3rd photo is no print heat & rollers that have been cleaned.

 

[davinciimports]

I do not know the answer to your question, but I have seen employees move the pinch rollers out of the correct location for the sticker guides. Are all your pinch rollers located correctly with the grit rollers? I see lines the media whenever the pinch rollers are outside the roller areas.
Probably not the answer, but just a thought.

 

[Sign Pro Salina]

Yes, we have made sure they are centered over the grit rollers. Thanks for the input.

 

[Solventinkjet]

If heat settings are making no difference and it happens on all medias, it's most likely contaminated/bad rollers. Cleaning them with alcohol is actually not a good idea because it causes the plasticizers in the rubber to leak out and cause issues like this. That, or someone got silicone or some sort of grease on them. Either way, you'll probably just want to replace them. Pretty sure Roland sells them directly on their site.

 

[flyplainsdrifta]

We had this issue on our Roland XF640. How old is the machine? Rollers wear over time and compress and harden. We tried alot of the same stuff you were trying and ended up just replacing the rollers about 7 years into the machine life. Took care of the issue for the most part.

 

[Sign Pro Salina]

If heat settings are making no difference and it happens on all medias, it's most likely contaminated/bad rollers. Cleaning them with alcohol is actually not a good idea because it causes the plasticizers in the rubber to leak out and cause issues like this. That, or someone got silicone or some sort of grease on them. Either way, you'll probably just want to replace them. Pretty sure Roland sells them directly on their site.

I also wondered about contamination. But thought cleaning them would resolve that. Our Roland tech started us cleaning our rollers with alcohol 20 years ago on our first Roland and we never had any issues for 14 years with the rollers on it or the 6 1/2 years with this one. However they only get cleaned when there are marks that start showing which is rare.

 

[Sign Pro Salina]

We had this issue on our Roland XF640. How old is the machine? Rollers wear over time and compress and harden. We tried alot of the same stuff you were trying and ended up just replacing the rollers about 7 years into the machine life. Took care of the issue for the most part.

Ours is 6 1/2 year old. So maybe time. We never had to replace them on our previous Roland that was 14 years old when it finally bit the dust.

 

[flyplainsdrifta]

Miss when they made machines designed for 10+ years. I can only imagine that the material used for the rollers has changed to something marginally cheaper and consumable, meaning you'd probably have to replace them in less time relative to the older models. How many rollers do you have on that model? We had a ton so it took a bit to replace them all. Either way, i hope that helps fix what is causing the rollers to leave marks/impressions.

 

[Sign Pro Salina]

Miss when they made machines designed for 10+ years. I can only imagine that the material used for the rollers has changed to something marginally cheaper and consumable, meaning you'd probably have to replace them in less time relative to the older models. How many rollers do you have on that model? We had a ton so it took a bit to replace them all. Either way, i hope that helps fix what is causing the rollers to leave marks/impressions.

Agreed, they are made more cheaply now. The are 6 middle rollers that are causing the issue and then it also has the 2 outer rollers. I too hope new ones will fix the issue, that's about all I can see doing next at this point. However we are waiting for a Roland tech to get back to us that is on vacation until Monday. We will see if her concurs about roller replacement.

 

[Jim Hancock]

Does this happen on different brands of vinyl? As you are getting the marks regardless of temperature settings, it makes me suspect the vinyl is softer than normal.

 

[Sign Pro Salina]

Does this happen on different brands of vinyl? As you are getting the marks regardless of temperature settings, it makes me suspect the vinyl is softer than normal.

We only have Orajet in stock. It is leaving the marks on both the Orajet 3951 RA w/ Pro Slide high performance & 3165 RA calendered. After cleaning the rollers & trying different temperatures, I thought it might be a bad roll of media. Switched to printing on 3951 and it has the same problem, even more so than the calendered media.

 

[Jim Hancock]

Try a different brand as a test.

 

[Jim Hancock]

Another thought... Often this problem can be alleviated by using only the outer rollers for printing, where media movement is incremental and slow and only the outer rollers are actually necessary, and then to use all the rollers for cutting, where media movement is fast and erratic based on the cut files instructions. The marks you are seeing are a combination of roller pressure marks and a very tiny bi-directional misalignment (I presume you are printing bi-directional) due to the media in the area of the rollers being a tiny bit further from the printhead due to the media being slightly compressed in those areas.

 

[Sign Pro Salina]

Another thought... Often this problem can be alleviated by using only the outer rollers for printing, where media movement is incremental and slow and only the outer rollers are actually necessary, and then to use all the rollers for cutting, where media movement is fast and erratic based on the cut files instructions. The marks you are seeing are a combination of roller pressure marks and a very tiny bi-directional misalignment (I presume you are printing bi-directional) due to the media in the area of the rollers being a tiny bit further from the printhead due to the media being slightly compressed in those areas.

I read that else where about leaving out the middle rollers. We were able to do that today for the shorter run jobs we had. However for longer runs, the vinyl won't track straight with only the side ones in. Yes we are printing bi-directional.