A problem in the second cycle of entering the paper for printing

There is a problem that has appeared in the gto 52 dds machine
When the paper enters the machine for printing the first time, the paper comes out of the machine in even colors and there is no problem.
But when the same paper enters a second cycle in the machine with the same colors and the same product, a phenomenon occurs that the paper comes out of the second cycle with an uneven color.
It has high and low colors
The blanket has been changed
The ink quality has been changed
But there is the same problem
There is a picture for clarification
You will find that the colors are irregular after the second cycle
https://www.raed.net/thumb?id=494215
https://www.raed.net/thumb?id=494218
https://www.raed.net/thumb?id=494216
https://www.raed.net/thumb?id=494219

 

You have registration issue pal.

 

Why do you mean there is a problem with registration?
Knowing that the first cycle of color is excellent and there is nothing wrong with it
The problem is in the second cycle

 

On the 1st pass colour will be the same regardless of registration. On 2nd pas if it's not registering correctly (dot to dot) there will be colour differences. It's like you'd print twice as much dots as at the first pass.

 

What do you think is the solution
Do you mean by registering to adjust the ink cylinders on the board?

Or by recording, you mean adjusting the pad cylinder to the blanket cylinder

 

I don't understand what do you mean.
Firstly check front lays and side lay - if paper is laying correctly on them.
Then check the cam follower on impression cylinder.

 

Is it possible to have pictures showing the places you want me to check?

 

It looks like from the photo you posted that your color is not consistent form sheet to sheet.
The density in the magenta is stronger in some sheets then others, for example.
I have had this same problem lately, and have tried different inks but no luck. My ink rollers looks like
they need replacing so that might be the culprit, I'll try that next. On a side note the registration was correct.
Have you tried adjusting the fountain solution?
I have reposted the photo of your sheets for clarification.

 

Not at the moment pal. It's really simple machine - just check step by step every stage of sheet travel through the machine

 

You're talking about different problem

 

What do you mean

Have you tried adjusting the fountain solution?

 

What do you mean
Then check the cam follower on impression cylinder.

 

Dear Ali,
I don't understand why you want to print the same sheets with the same colors again.
It's impossible to print dot over dot typically.

 

Sometimes the paper needs to go through a second round
It is assumed that when the paper enters a second cycle, it will have a fixed degree of color, but what happens otherwise is that one sheet of paper is a dark color and another sheet is then a lighter color.

 

But why you print one colour twice instead of changing the artwork???
It's ok to do double hit when printing solids, but not screens.

 

And that 8s because of bad registration. You're doubling the amount of dots - that's why it's darker

 

As a reminder, not all paper is dark in color, and also the dark color appears in the last quarter of the top of the paper.
And how to adjust the intended recording
Is it adjusting the ink cylinders or adjusting the printing cylinder with the blanket cylinder?

 

Check:
- if plate thickness is correct
- if blanket plus packings thickness is correct (as I can remember is 3mm in GTO)
Even if your registration is correct (but I don't think so) then if your blanket is overpacked or if you print at too much impression your paper may be stretched. Just check plate and blanket - change it to 3 mm if needed and give it a try

 

I checked the blanket and it is indeed 3mm

 

Are you using the the correct grain for the paper is the paper crap