Bio Ink(Soy based)

[Copper]

Switched to Bio Ink recently. Anyone having luck running this Ink? I run a Man Roland 700(1997). Recommended by our Etch supplier, we are running Etch at 2.75% and a Sub at 1%. We are still running with the same water forms as we did with the conventional ink. I'm having to run my water form speed much higher and it's unpredictable(dry-ups,keeping screens clean). Should we try a softer water form? Change etch settings? Never had problems like this with conventional ink. Flint is our ink supplier and has been for 10 years. Any help or tips would be great!!

 

[Copper]

copper

copper

On a side note..our conductivity is around 2300 and ph is 4.9. We are mixing buy hand incase our dosers are not working right. Still the same out come. We use RO water and yes it's at zero conduct.

 

[jbeniston]

Use the mid point average of the etch manufacturer’s recommended dosage for the amount to be added?
If it's 3~4 oz per gall then take the midpoint and use this: 3.5 oz per.
Multiply this by .78 to give you the requirement as a percentage and set the "etch" doser accordingly.
The dosers don't very often fail. You could overhaul them. Clean thoroughly in warm water and make sure the one way valve where the etch comes out of the doser, is not stuck.
If you dismantle it, be extremely careful that you do not lose the little spring or the tiny plastic ball inside. When you reassemble watch out you do not over tighten the screw as you can snap them easily.
It sounds to me like the wetting agent additive is a bit too low, which is why the roller speed has needed speeding up. Again, follow the same procedure as that described for the etch.
You don't have enough "wetting agent" in the system to work properly.
If you have the dampening system set to specs, rollers in good shape and the dosers all working properly, you should talk to the ink supplier.
If he hasn't got the water pick up stabilised at a workable level then there is not much you can do at the press. The ink should pick up dampening fluid quite quickly and then level off. Normally an ink can hold up to 50% before it becomes a problem. If it just keeps going up, you will have no chance to run this ink properly. Are you just testing this ink? If you are trying to run it in production and you're having problems, get hold of the ink manufacturer, as you do not have the time to play around trying to make his ink work.
Now and again a dollop of body gum in the ink helps, but this is a band aid remedy not a solution.
Once you've got all your ducks in a row, rollers and dampeners set to specs, no out of tolerance durometer, dampening fluids set to the manufacturer’s recommendations. Why should you have to alter everything just to make an ink work?
Hope this helps you out
Good Luck

 

[Copper]

Thanks Jben..very good stuff. No we are not testing the ink we switched full board. We switched to the lower VOC ink because of a few Gas Ghosting jobs we have problems with during the year. Honest, with the other ink most of the Gas Ghosting problems we had were because of the head pressman running them wrong(not running the heavy side first,not running small loads..ect). We are forced to run Soy ink and it stinks. We never had to run a sub before and color came up fast and was predictable through the run. No one wants to hear it and we're stuck with a sub par soy ink.

I'm actually going to print your response and sow it to my ink rep...who is great but has his hands tied also.

thanks, mark