ValueJet 64" Roller Impressions on banners?

[SignsRus]

I can't get a good photograph to show you exactly what's going on here

BUT

I tried printing some green banners yesterday...for the first few feet of the print you could see the rollers on the material...like light spots in the print the exact width of each roller touching the material

anyone think this is happening because of too much heat or not enough?

im at a loss

edit: here got a decent picture

 

[Graphics2u]

I have fought this same issue for as long as I have been printing! Had a Falcon Jr. that did it, and a Falcon II outdoor that does it. I have never been able to figure it out. Heat doesn't seem to make much difference. It's almost like a residue is left from the rollers that causes the ink not to flow correctly. I have had certain types of vinyl also do this like orajet 3640 gloss. And some other materials also.

Usually once you print for a few feet it goes away but that doesn't explain why it's happening.

I know I wasn't any help, but sometimes it's nice to know you're not the only one with the same problem.

 

[graphixtogo]

what brand/weight banner material are you running?

 

[SignsRus]

I have fought this same issue for as long as I have been printing! Had a Falcon Jr. that did it, and a Falcon II outdoor that does it. I have never been able to figure it out. Heat doesn't seem to make much difference. It's almost like a residue is left from the rollers that causes the ink not to flow correctly. I have had certain types of vinyl also do this like orajet 3640 gloss. And some other materials also.

Usually once you print for a few feet it goes away but that doesn't explain why it's happening.

I know I wasn't any help, but sometimes it's nice to know you're not the only one with the same problem.

EXACTLY after a few feet the issue disappears....I think it either has to do with something on the rollers or the material not being the correct temperature when it starts printing.....

 

[SignsRus]

what brand/weight banner material are you running?

ultraflex 13oz

 

[jiarby]

Read this thread from last month...
http://www.signs101.com/forums/showthread.php?t=27346

RandyA at Mutoh suggested at forst that the rollers were contaminated and a good cleaning with alcohol would clear this up.

Then later on he suggests to leave the rollers in the UP position after a job.

I think this means that they believe that the rollers are too soft (design problem??) and getting flattened on one side. As you print the rollers get warmed up and go back to normal. The out of round rollers are squeezing the vinyl plasticizers in the pattern you see because of uneven pressure created by the flattened rollers

<note>
this is my personal opinion...
</note>

NOTE:
This also happens to me with the UltraFlex 13ox Matte...which I think is "softer" than other banner scrims I have seen. I have also experienced it on 60" Oracal 3651 & even a 24" roll of 651.

Is this a JetFlex/Mutoh combination situation?? What sized roll are you using? Full roll (heavy) or partial??


Try rolling a few inches of vinyl back & forth a few times with the control panel...the theory is that the rollers have flattened out and you are rounding them back to normal.

 

[Valentino]

I've gotten this before. your pre-temperature's too hot, making the material too soft and allowing the rollers to leave impressions, turn the pre heater down to 35 degrees Celsius

 

[jiarby]

I've gotten this before. your pre-temperature's too hot, making the material too soft and allowing the rollers to leave impressions, turn the pre heater down to 35 degrees Celsius

It's the rollers getting soft & flattening out on the bottom. That's why it looks like ridges instead of a constant flat area.

It may be too much preheat making the rollers flat, who knows for sure??

 

[Valentino]

my understanding, at least with my valuejet is that the material is too hot.

I would suggest trying temp down at 35 and printing 2 feet of banner material.

 

[randya]

Most of this effect that I have seen has been on non-ValueJet machines and has always been some form of contaimination.

As jiarby points out the ValueJets have a softer material for the pinch rollers and the pattern seems to suggest some kind of flattening effect and media interaction.

I run Ultraflex mostly for banner material (FL) and personally have not seen it on my machines. But I dont run a shop, just a demo room.

If someone who is having this issue can run some tests, it might help figure out exactly what is going on.



Find a way to make it happen on purpose.

Take some good notes.
Room temp, media, printer heater settings.

Make an image that exhibits the problem and put blank space in the image so that the first x inches prints nothing.

Is the effect gone? Every time?

Sorry, I dont have a better answer at this time.

BTW, I normally run Ultraflex at 35/38/50.

I have been trying 42, 35, 50 in some tests to reduce head strikes on 98" wide media that has been sitting and is bowed.

 

[D&Tgraphics]

I ran a 8x4 print earlier with a green background on 3651 and the first couple of feet looked exactlly like your picture. My temp on the pre heater was 37 and the rollers are never left down when not printing. ??????