Wrinkles while printing?

First time poster, long time lurker... I started a new job and we are printing on lightweight material 115 gsm and 145 gsm. The media widths are about 3.5m and 5.3. We are using a custom built (by the manufacture) bulk feed mechanism going into a Uvistar pro8.

My original thought is that the bulk feed was out of alignment to the printer. Fixed that and had success for a while. Then the roll became smaller and obviously weighed less... We started having a lot of creases again... I aligned it all over again and I still get creases.

Second thought is the bulk feeder and the shaft can't support the weight of the bulk roll. As it gets smaller we seem to have more issues. -I can see the whole frame and shaft flexing under the weight of the bulk rolls on a 3" core. Could this be an issue? Is a 3" core too small? As it sits, the middle of the roll sags a bit.

Third thought, the rolls came with wrinkles?

Any insight or ideas would be appreciated.
 
Sounds like a load issue or moisture in your material. Given the massive amount of exposed surface area, this paper will absorb moisture like crazy. I wrap my paper in shrink wrap immediately following a print run. It cuts down on a lot of problems.
I suspect this is your issue considering it gets worse as the roll is on the machine longer.

Another culprit can be over inking. You may want to experiment with tightening up your ink limits.
 
Another culprit can be over inking. You may want to experiment with tightening up your ink limits.

Interesting... That is definitely an issue that I am getting looked at in the near future. Currently we are putting so much ink down it is mind blowing. Are you thinking the excess ink adds a lot of weight which throws things out of balance?

The material we are using is pe (plastic) so I am not sure if the moisture could be an issue or not, totally makes sense with paper and would have not thought about that. I will check with the manufacture. However the wrinkles happen before it even gets to the print area so I can't stop thinking that it is the custom bulk feeder. It just doesn't seem strong enough for our application.

Thank you for the comment!
 
Ahh...i didn't know it was plastic. Yeah with paper...it can turn into a soggy cracker. The ink covered (or unwanted moisture) areas will buckle if tension is off in the least.

If the material is getting flexed too much I think your assumption is perfectly reasonable. We've had that with fabric where the stock flexes too much and it actually stretches the middle of the roll.
It will pucker up in the middle and there's a real risk of head strikes. We try to always move it with the spindle in it so it minimizes the issue. The less agitation before the machine the better.

You may want to mess with heat settings on your platen too.
Too much is just as bad as too little. Same with tension. I've found is less is more in both of these instances.

Another thing could be your rollers are dry. Maybe wipe them down with some distilled water to get an even purchase down the length of the pinch roller.

Best of luck!
 
You may want to mess with heat settings on your platen too.
Too much is just as bad as too little. Same with tension. I've found is less is more in both of these instances.

Another thing could be your rollers are dry. Maybe wipe them down with some distilled water to get an even purchase down the length of the pinch roller.

Best of luck!

Thank you for sharing your knowledge Andy! I really appreciate it.

These are UV so no heat settings that I know of.

Will experiment with the distilled water.

Loading.... Funny that you mention that. When we load internally, I am not seeing the wrinkles. Sometimes we load "older" material on the bulk feed and see 0 issues... So I am starting to question our loading technique as well.

Problem is that I am working with inexperienced people that don't know much about mechanical devices let alone printers. We are seeing improvements but we really haven't solved the problem just yet. Ultimately I think it is the inexperience and those same workers have been in charge of maintaining these machines... The more I dig the more I find wrong so I am attempting to correct those mistakes and bad habits.

Thanks again for your advice!
 
In the past I had a 3 meter Scitex that could not print more that 10 feet of material before it wrinkled. Called Scitex and they said its a material problem. Called material vendor and their response, wait for it..... its the press, they said. So finally after months of this, we put a level on the machine and it was 5/8" out of level over a span of 12 feet. We leveled the machine and found that was the issue. A few months before this, we pointed out to the engineer that the levels on the machine showed that the machine was not level. Engineer's response was I leveled the machine myself, I am sure it is level. He then proceeded to adjust the levels on the machine to make the show level.
 
It really is all about the load. I have 100 foot prints sometimes...and have loaded it to run 400 linear feet of paper. The thing about these long runs is the tension issues get worse the longer it goes! And if you make adjustments while it runs...sometimes it looks good but the the issue doesn't show up for 10 or more feet. I learned about surface tensions and moving material from blueprinting in the 90's! Also a big Seal laminating and mounting press. On roll to roll if you try to adjust on the fly...it has to be tiny increments. Something else I've found is I let my material walk loose on the roll. I just let the pinch rollers lock it down and material can float. The real trick is to load with some slack and pull taut, using the parallel nature of the rollers get you square. Sometimes the material walks...but we can square everything up in finishing. Dye sublimation is weird because the paper is fairly rigid, but the heat and tension on the fabric makes it like putting a temporary tattoo on taffy! The better the load...the better the product on all of this stuff!

We have to not only load the print well...but the material transfer well too! I've lost 40 and 50 footers that were perfect prints...but died in the heat press.

Pic 1 is about 300 feet of PMS 485C for E3 last year. (Check out that load...obviously I was proud enough to take a picture...hahaha)
Pic 2 shows the paper to fabric process.
 

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In the past I had a 3 meter Scitex that could not print more that 10 feet of material before it wrinkled. Called Scitex and they said its a material problem. Called material vendor and their response, wait for it..... its the press, they said. So finally after months of this, we put a level on the machine and it was 5/8" out of level over a span of 12 feet. We leveled the machine and found that was the issue. A few months before this, we pointed out to the engineer that the levels on the machine showed that the machine was not level. Engineer's response was I leveled the machine myself, I am sure it is level. He then proceeded to adjust the levels on the machine to make the show level.

That is amazing to me. Rather than admit that he did something wrong he went and caused a lot more strife by adjusting the levels!? I think his title of engineer should forever be tarnished. You can't do things like that! What is wrong with people...
 
Something else I've found is I let my material walk loose on the roll. I just let the pinch rollers lock it down and material can float. The real trick is to load with some slack and pull taut, using the parallel nature of the rollers get you square. Sometimes the material walks...but we can square everything up in finishing.

That's interesting, we were working on this with one of the owners, he insisted to not let it walk on the rolls. I am not much of an expert so I said okay and clamped off the cores... I'll have to experiment with this. That is a pretty impressive print of 485c! Look how straight and perfect it is on that roll. :)

I really think we need to work on our loading technique, I am going to try and see how things work loading with slack. That makes sense to me as well... Our prints don't need to be perfectly square so I'm not too concerned with squaring up in finishing if the media does walk.

Ultimately I am finding maintenance issues, media issues and technique issues. So what I think is happening is some rolls are just fine, and others are bad enough that it compounds all of the above to make printing one design nearly impossible... We have made progress so far and have successfully printed on some rolls that were deemed "bad" so I am seeing the light at the end of the tunnel! Either way we have a lot to work on and fix. I really appreciate your advice Andy!
 
Gentlemen,

For us to offer more assistance with this problem, we need from you A diagram of the "Web/Substrate path only up to

where it enters the Printing Area Mechanics",



I enclose a PDF which I hope you will find of interest and value.


Regards, Alois



Hi Alois, PM me your info as we are looking in to some better shafts. Not sure if you offer that or not? Wait, I assumed that you sell rollers or shafts? Please disregard if not.
 
When I say on the "float" I mean in the paper direction. We have these hefty steel spindles that have an air bladder. You air charge them and it locks the tube to the spindle.
I let new stock roll freely, but lock down spindle at front. We also guide the material with clamps if it is walking...but it's important to do it intermittently and gradually.

Techniques are different for all substrates, and you're right about maintenance! I'm constantly cleaning and servicing...our environment is less than controlled. :)
If you rule out these types of factors you can concentrate on only the throughput, which is key. Process control is where it's at. We're sure to follow the same procedures, in the same order, every time.

The only way you get problems like this solved is time and projects! Best of luck to you!

Andy
 
When I say on the "float" I mean in the paper direction. We have these hefty steel spindles that have an air bladder. You air charge them and it locks the tube to the spindle.
I let new stock roll freely, but lock down spindle at front. We also guide the material with clamps if it is walking...but it's important to do it intermittently and gradually.

Techniques are different for all substrates, and you're right about maintenance! I'm constantly cleaning and servicing...our environment is less than controlled. :)
If you rule out these types of factors you can concentrate on only the throughput, which is key. Process control is where it's at. We're sure to follow the same procedures, in the same order, every time.

The only way you get problems like this solved is time and projects! Best of luck to you!

Andy

Thanks for clarifying on the float.

Exactly- time and projects... Practice, practice, practice!

I actually started looking for steel shafts/spindles with air today. Any recommendations on a decent supplier if you are in the US? I guess we had a welder make them in the past (no air bladders) but I am concerned that they may not be built properly...
 

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