50# uncoated text on Indigo 5500

[pius222]

Hi there's a note pad job that is 4/4 duplex, we use GPA 50# uncoated text, but somehow causes press stoppage. sheets will stuck on impression drum, and will have a folded corner and wrinkles. Not sure if any of your guys experience this. Contacted both GPA and HP.

Only GPA responded, tried these steps:

1. Check the substrate definition, make sure the length is correct and on Matte and uncoated - checked, still problem.
2. Transport simplex - no problem.
3. Transport duplex - problem.
4. Print simplex - no problem.
5. Print duplex - problem.
6. Go to Diagnostic > Substrate > Perfector & Conveyor > adjust Perfector A and Perfector B from default of -1.9 and -1.4 to -2.2 and -1.7 - problem. I also went a little further as -2.7 and -2.1, still problem.

Problems on both 12"x18" and 13"x19" sheets. The exit roller is in place. Anybody have any ideas how to resolve this?

Thanks,

Randy

 

[jinthebay]

Hey Pius. I run a 3500. Always have trouble with 50# text. Firstly, check your grain direction. If it's correct then try this. Change the GSM for that paper definition to 111. (That being the lowest for Range 2). Perhaps even jump up the thickness of that substrate to .08.
I've had all kinds of problems with some of my lower weight papers but none more than the 50# offset. Hope this helps.

 

[pandus13]

Given this is cold season, did you accustomed your substrate? (let it come up to shop temp and humidity).
i think there is a tool that measures the humidity of the paper....

could you run this as a 2 runs simplex? remember to live a bit of time space between the runs (to discharge electrostatic (which i'm guessing is causing to stick to drum=wrinkles) and get some humidity in the substrate)

some papers are just that... strange.... the next batch could behave OK...

 

[cbucheli]

It looks like your sheet is hitting the grippers when it prints on the second side. Adjust the front gripper first around 8.5-9mm and the back to 6.5-7mm.

 

[pius222]

Thanks all, today HP tech came in and first replaced the grippers, then he adjusted the Diagnostic > Substrate > Perfector & Conveyor > adjust Perfector A and Perfector B to -2.4 and -1.9, and somehow this time it worked...

I'll have to run more to see if it indeed resolved the issue. I think the machine being first warm up in the morning vs. in the afternoon where after many impression printed, the static amount in the press plays a role in the buckle.