Gto 52 Dampening Problems

[marc]

My ink is turning milky which i have put down to the dampening solution transfering up the ink rollers i have altered the dampening but i either get milky ink or solid ink across the blanket
I have just recieved a full set of ink and dampening rollers but before i replaced them i have noticed that the new dampening rollers are 3 mm smaller in diameter i have been in touch with the company i got the rollers from and they have told me that these are the right dampening rollers
I have tried to fit one of these new dampening rollers but they are no way near the plate no matter how much i adjust them

Any Help Welcome

 

[Borut]

Hello
I think that the new rollers are not ok because you can't get the right contact. What kind of ink you are using?
You should check the dampening solution. What dampening system do you have? -DDS
Regards

 

[marc]

Thanks for replying currently using sheet fed trans white or thermgraphic varnish
The gto is used for thermographic printing
Not sure what dampening is used all it has is one brown coloured dampening roller that touches the plate and also comes into contact with a chrome roller ,the chrome roller comes into contact with a roller that has a red plush material covering which comes into contact with another chrome roller that is sat in the dampening trough
Also what am i checking the dampening solution far
Hopes this all makes sense

 

[Borut]

So you have 4 rollers in dampening system Is it alcolor, clasic system or kompac

 

[elektorus]

I think i know what is the problem. You have right now Bareback dampening on your machine.
Bareback dampening uses 2 or 3mm diameter bigger roller (on the plate) than molleton roller which must have fabric sock on it. Your supplier gave you classic molleton roller, that needs cloth. Thats why you cant adjust it to the plate. You need to decide wich dampening system will use, bareback alcohol or clasical water dampening (molleton).
As for milky ink, it will not happen if you use molleton dampener and adjust level of dampening solution adding.
I think your current problem is : Either you have too much IPA in dampening sollution, or your dampener isnt adjusted properly.

 

[marc]

Thanks for your help
Currently not using IPA using vanson fount solution with no additional alcohol
Tried adjusting dampening roller but i either get water transfering up the ink rollers or not getting a clean plate with ink slowly filling up from the edges into the image area
Might cover the new dampening rollers and try using them are they set the same as normal

 

[mrheidelberg]

Hi Marc

Still a little confused to what is going on, the ends of the dampers should be painted green and the diameter for the conventional cloth covered rollers should be 45mm and bareback rollers should be 48mm. The vibrator roller will be cloth covered in both systems and should be slightly longer in rubber length but not in core length.
There are a few threads in this section which deal with GTO damper settings.

Regards.

 

[elektorus]

Thanks for your help
Currently not using IPA using vanson fount solution with no additional alcohol
Tried adjusting dampening roller but i either get water transfering up the ink rollers or not getting a clean plate with ink slowly filling up from the edges into the image area
Might cover the new dampening rollers and try using them are they set the same as normal

Bareback dampening is very sensitive on worn bearings, and is also very hard to adjust. I use to do it and it was very time consuming. Some machines
If you have covered dampening rollers, adjusting iz easy, but there is generaly a quality isssue.
Main thing in printing with clothed rollers is :
when you are preparing machine, you should first, take out the rollers (3 of them, 2 on the plate + 1 vibrating roller) and moisterize them with dampening solution. Be careful, do not soak them, or bath them in solution, just use soaked spunch and scrub them with it. Then put them in the machine, start running, and put dampening first on the plate and make shore that the plate dampening is ok, then try puting ink rollers on the plate.
As for setting dampener rollers on the plate, we use to do it with the film strips, it isnt that sensitive and is pretty easy to adjust.
Either way i would reccomend installing Kompac 3 dampener, we have it in our printhop on Praktika and it is fantastic. Waste reduced, quality improved, easyer to run etc.

 

[marc]

You say that if i have covered dampening rollers ,adjusting them is easy but there is generaly a quality issue
What quality issue do you mean
Currently i have only 1 dampening foller on the plate because i cant find the chrome roller that sits between the 2 rollers onto the plate
Would using 1 roller be ok or would it be better running 2
So is it better and easyier to use covered dampening rollers then bareback and do i have to remove them when washing up or can i still engage all the rollers to the plate as i do now

 

[marc]

This might sound a daft question but what do i cover the dampening rollers with is it the same red plush material sleeve that i have on my viberating roller the one after the chrome roller that sits in the dampening tray full of dampening solution

 

[bluebeep]

My ink is turning milky which i have put down to the dampening solution transfering up the ink rollers i have altered the dampening but i either get milky ink or solid ink across the blanket
I have just recieved a full set of ink and dampening rollers but before i replaced them i have noticed that the new dampening rollers are 3 mm smaller in diameter i have been in touch with the company i got the rollers from and they have told me that these are the right dampening rollers
I have tried to fit one of these new dampening rollers but they are no way near the plate no matter how much i adjust them

Any Help Welcome

Have had this problem before.
sounds like its not the dampers at all, size of dampers ok. Put yours BACK.
what stock r you printing on. I think your running too much water cut it
down and soften the ink a little to allow the ink to key on the image on the plate. change water solution, The water sounds Strong check PH value
try a little alchol also is coating of stock makig the milkiness

 

[elektorus]

You say that if i have covered dampening rollers ,adjusting them is easy but there is generaly a quality issue
What quality issue do you mean
Currently i have only 1 dampening foller on the plate because i cant find the chrome roller that sits between the 2 rollers onto the plate
Would using 1 roller be ok or would it be better running 2
So is it better and easyier to use covered dampening rollers then bareback and do i have to remove them when washing up or can i still engage all the rollers to the plate as i do now

By quality issue, i mean that its generaly harder to maintain ink density, then ther are hickies especially in start when clothing is stil new.
1 roller is good when you are using bareback, but if you are using clothed rollers ther shud be 2 of them on the plate, because dampening has more stability.
You dont need to take out dampener rollers when you wash machine, just dont set them on the plate, you also dont set inking rollers on the plate. Generaly speaking clothed rollers need to be washed, once a week or even rarely if the arent scummed with ink. When you do wash them, wash them out of machine manualy with water and detergent i mean scrub them with hand brush. then you need to dry them. Ussualy you do it at the end of shift so they naturaly dry in the morning.

 

[marc]

Hickies aren't a problem as only overprinting in clear inks wont show that much the trouble is keeping the ink/varnish open without drying/curing because it needs to be tacky for the thermographic powder to stick to
I will have a look at my bareback dampener and check the bearings and also check it against the plate in different postions to see if it is concentric
Hope this makes sense might just get a new roller so i have s spare just incase the one i am using is no good
Thanks for all your advice

 

[marc]

Press seems to be running ok
Still using bareback dampening but have noticed that the barback dampening doesn't touch the chrome roller until i engage the machine to dampening but i am sure it used to be in contact all the time
Also is there anything i can put on the grippers through the machine to stop them leaving any gripper marks only visible on stiff board
Also having trouble in keeping the ink open on dry board you can see the image fine but it appears to be absorbing into the board
Hope this makes sense
Forgot to mention that i am using the press for thermographic printing so need to have the ink or varnish open/wet/sticky (call it what you want) for the thermographic powder to stick to

 

[mrheidelberg]

The plate damper needs to have contact to the oscillating roller. Set it to a 4-5mm ink strip and then 3mm to plate.
To get rid of the gripper marks the gripper timings may need to be reset or you could just back the front lays off slightly to give a bit less grip.

Regards.

 

[marc]

Thanks but does the plate damper have contact with the chrome oscillating roller all the time or only when i engage the machine into dampening

 

[mrheidelberg]

Yes the plate damper has to be in contact with the chrome oscillator all the time.

Regards.