Some Lines on Plate

[rafaqat]

We are facing some line on our Chinese CTP plates. Its lines through the image and the end side of the plate. Please see the attached .
We are using Screen PTR 4100 CTP machine.

 

[ansoft]

If you try another batch, or another brand of plates, do you still have these lines? Probably, you need to make focus, zoom and drum rpm tests.

 

[rafaqat]

If you try another batch, or another brand of plates, do you still have these lines? Probably, you need to make focus, zoom and drum rpm tests.

Some times the lines disappears automatically and after some days they appear again.
We have calibrated the focus and zoom. it shows that our focus and zoom values are already correct.
we have tried changing plate. it is not working

 

[Aleksey]

It's difficult to judge on your pictures, but looks like wrong zoom. Disappearing/appearing of lines can caused by many factors: different thickness of chinese plates, different temperature in your workspace, problems with zoom/focus motors.

 

[rafaqat]

I measured the thickness..... standard thickness should be 0.3 mm here are the results,
1. 0.27 mm
2. 0.25 mm
3. 0.26 mm
4. 0.27 mm
regarding our temperature, the user manual describes between 19 c to 24 c we are following that.
Please guide us how we can overcome this issue....

 

[kermudgen]

I had a problem like this on our ECRM image setter two years ago.
It was corrected by replacing the encoder.

 

[ansoft]

It could be the data cable to the head. It is very common problem on 4xxx Screen devices.

 

[Aleksey]

Please guide us how we can overcome this issue....

Dear colleague, I'm sorry, it's my mistake. I just magnify your pictures and saw that distance between lines is not equal. It's problem not with focus/zoom/temperature.
I had same problem with one type of Chinese plates. Try to decrease drum speed for 100-200 rpm. Also problem can be caused by ballscrew - you need to grease it by special solution, but better way to ask your service about greasing.

 

[rafaqat]

Dear colleague, I'm sorry, it's my mistake. I just magnify your pictures and saw that distance between lines is not equal. It's problem not with focus/zoom/temperature.
I had same problem with one type of Chinese plates. Try to decrease drum speed for 100-200 rpm. Also problem can be caused by ballscrew - you need to grease it by special solution, but better way to ask your service about greasing.

Thank you, I Shall try to reducse the drum speed.
Can you please tell me the working and effects of Drum Speed, Focus, Zoom and laser power on plate.

 

[rafaqat]

I was suspecting that lines are appearing because of uneven thickness of plates.
We are also using GTO 367x450x0.15mm plates and lines are not appearing on this sort of plates.

 

[Skinflint]

what is the humidity at in the room?

 

[rafaqat]

what is the humidity at in the room?

working hours we maintain 50 to 55,
off hours 80 to 90

 

[erictoray]

Can you turn the plate 90 degrees and image it to see if the lines run with the imaging head or with the plate? That should give you a better idea of if the problem is in the ctp or with the plates.

 

[ctprudman]

Bottom line is if you do not use the same manufactures chemistry and settings then the problem will not be detected in the manufactures quality control department and you are basically doing your own R & D ..... Try Xingraphics Primus Plus or Invado plate and chemistry they are simply a real long term alternative to Agfa Fuji and Kodak equivalent products