plate blinding

hello everyone. I am running a 2021 CX104 Heidelberg 5/C. I have plate blinding going on in one unit only. I switch the black to another unit and its fine. I reset the rollers multiple times and to me everything looks ok. I must be missing something but not sure what it is. I tried vario off and on and also integrated bridge roller. Water form to matte stripe 7 chrome to water form 6 bridge to water form 4. we run vario on and non integrated all the time. Is it possible this is all bridge roller related. Thanks

 

Please check the ink-form-rollers. Normaly they are not having movement from left to right, they are locked.
Form-roller to oscillat.-roller 4mm. form-roller to plate must have 1. (white) 3.5 to 4mm, 2. (blue) 3.5 to 4mm, 3. (red) 3.0 to 3.5mm, 4. (yellow) 2.5 to 3.0mm. dampening (water) form roller to plate 4.0 to 4.5mm. Try to start production without contact bridge roller to 1. ink-form-roller.

 

thank you, I forgot to mention I run UV ink. does that make a difference? What would you set the water form to matte and the chrome to water form? I have set rollers 100 times and never had these issues.

 

what do you mean by plate blinding , please if you have some picture send me to see

 

I don’t have a photo right now since we switched units. Basically on very light coverage on the black type it just disappears. Seems like water overpowers the plate. The plate is not wet when you look at it. The scum line is excellent. When you try to take water down it dries up.

 

1. check the package at blanket cylinders. should be the same from one unit to others. can you measure it? renew undersheet, maybe it would be better to change type of blanket, what type is in use?
UV print isn´t that easy. The ink should be always in movement inside ink pan. IMPORTANT: If there is a window near the unit (which has the problem) and sun light coming in, its bad - if there is a inline-dryer near blanket cylinder in the unit which has the problem, its bad too. Lots of diferent issues ...

 

We were running ok. then our bridge roller brackets stripped. Changed both brackets drive and operator side. Now we seem to be having this problem. I set bridge to water form roller about 4mm. then spring tension to white form (first form). Do you think this can possibly be all bridge roller related. We run nonintegrated anyway. Im going to take it all apart and start over. Thanks for your reply

 

Dampening roller setting: water form-roller to matte oscill.-roller 6 to 7mm / chrome roller to water-form-roller should have more than 6mm - this is too week and cannot run good. Because when running with VARIO SYSTEM you need a bit more pressure. Set the roller presure here - 8 to 10mm. Bridge-roller will never ever given so much influence and 3.5 to 4mm stripe is o.k. in both direction. Try to disconnect bridge-roller from ink-system !!!

 

8 to 10 on chrome. ok I'll try an 8. We were making it a 6 because we kept getting too much water in the ink train up to the Ductor roller. We always run with the Bridge disconnected. One other question. What is the purpose of the Matte chrome. If you make the water form bigger there is that more or less water? Thank you for your responses they are helpful.

 

Dear Sir
Did you use baked plates.
I mean do you put your plates in an oven before printing.

 

No we don’t. Haven’t done that in about 15 years. Just through a processor. It just happens on one unit. I move my black to the 5 th unit it runs fine. Something is not right with my first unit. I feel like I set them all the same.

 

Please send me some picture to understand the issue ??

 

thanks for all the advice. Im going to pull apart and reset to Heidelberg specs

 

You should try to decalcify your rollers first unit usually gets all the clay and paper dust build up.recomend bottcher calcium fix

 

thank you. I've done that but will try again. its a strange issue. sometimes after you run some sheets the plate is clean in some spots like it was never used. mostly in the areas where there is not alot of work

 

according to your last message I think it's just a balance problem between the quantity of water and ink please check the intermediate roller (adjustment and play in the adjustment mechanism) while waiting to give me photos or videos to know what is happening

 

Hell Adil, I rechecked the bridge setting. I have a 4mm to the water form and that made a 5mm to the white form roller. Dropped form and dampener rollers to plate turned knurled screw to block then 1/4 turn more. ran non integrated started to dry up mostly on the operator side. when I went to recheck the bridge, I noticed it was touching the white form on operator side but not on drive side. Never had this before just wondering why it would be touching while not integrated. I did turn the knurled screw an additional 1/2 turn more after I saw the dry up, it helped clean it up. Just don't know if that's the right thing to do.

 

You need to take 2strips of light paper.and insert between white form roller and bridge drop all rollers and water form on plate if you are non integrated you should have no tension on the strip. If you are touching readjust.make sure you select non integrated on cp2000

 

You should also be aware that running vario on shortens life of water.form. 2 shifts running UV they will be shot in 6 months

 

thanks Jack. Didn't realize the life span would be cut that short. I noticed when we wash the rollers, they are very tacky to the touch. if you take one out and put it on a table it's like someone glued it down. crazy. If the bridge is toughing the white form while nonintegrated is the knurled screw the adjustment for that? Heidelberg says to the block and 1/4 turn, but can you go more if you have to?