metering roller issues

[pudgyboy]

Hello fellow printers.

I am having an ongoing problem with an excessive amount of ink build up on
my rubber metering water pan rollers. We have recently tried to put new rollers in to no
avail. We run Saphira etch along with about 10% alcohol in the mix. Inks are flint inks.

I believe it is chemical related, but am not sure exactly where the problem lies. i have to clen the metering rollers several times a shift which is a pain.

Any suggestions would be appreciated!

 

[printr640]

My first thought would be that your chrome is sensative. Try some good chrome roller cleaner or comet.

 

[arfamoe]

You may want to try adding a few ounces of 14 Baum Gum Arabic to your fountain solution, dont use synthetic gum only use the real stuff.

 

[Dan Roll]

You might want to test your alcohol for miscibilty and defoaming potential....

 

[Paultheprinter]

hi there,

for ink to end up on the pan roller it has to travel over the chrome metering roller, for this to happen i believe the ink must be held in suspension in the water to do this, the only other way this could happen is if the chrome metering roller were to have run dry. I have seen this many times and there are many causes but i think its caused by an over wetting of the ink or an excessive breakdown of the ink itself, the first problem is usually caused by high temp, contamination inconsistant fount mix or excessive use of additives. The second is caused by heavy ink nips or too much osscilation. There are issues like calcium which lead to excessive water feed and inconsistancy in emulsification but practical mantanance plans can cure most of the simple problems.

paul

 

[spider]

Metering roller

Metering roller

If the roller, which transfer the water to the dampening roller is set to hide.
You will get a buildup of heat, which will evaporate the alcohol and cause a build up of ink and transfer ink to your water system.

Try and get of a very light setting to the dampening roller. the trick is to get the speed
down on the metering roller and to open the roller up with out getting the roller to splash
on the ends,

You are looking for a light film of water on the roller

 

[spider]

Idea, use a laser beam to control the dampening

Idea, use a laser beam to control the dampening


Before I was made redundant, I was working on the idea, that we could use light to control the water system. The idea was to bounce light of the metal plate. As you know if you go into the unit with a torch or a flashlight depending on what country you are in. And you shine the light at a 45° angle you will get the reflection bouncing back into your face. You will then see the moist part of the plate and the wet end.
The damp part of the plate should be the print area, where the paper removes water from the plate.

What I'm trying to say is. Why can't we use a laser beam to control the dampening system?

Start thinking

Eddie

 

[printr640]

Hummm laser beam. That would be cost effective

 

[spider]

It could save a lot of money on running press it would be fantastic on a cold start UPS.
And reduce the amount of build up on the blanket because it would automatically increase the water when the press Starts to heat up. Just think. Fewer blanket washes, less waste.
Before the ink control system came out I used to say that one day a computer would do this work.
That's when we had seven people on a press. AND NOW reduced to just two on a 32 page four:
And they used to laugh at me. And said I was a dreamer