Coating foaming on press

[jon g]

Looking for help with an issue with coating foaming on press. We run a roland 700 press with anilux coater we use conventional coating but recently have had problems with air in coating.We have changed pipes, cleaned the system, checked pumps for wear , tried different coating , tried different pump speeds slower and faster, tried keeping pipes straight all with no success. The problem seems only to be an issue when we print on b1 size material. Any ideas would be gratefull for some feedback pumps are watson marlow and until two weeks ago we never had any issues

[Freeman A.Gain]

Are you using the Printcom coating? We've had quite a bit of problems with that also. Tried barely setting the return pipe in, to try and lessen the air into the coating. Funny enough, it doesn't happen with another coating that we also use. BUT.. ManR claims its the operator?? I'd advise you to try the pipe thing or keep looking for one that works, consistently! If you do resolve your issue, could you post it so we can try it also?

[jonprintz]

It definitely sounds like a problem in your system. To help with the foaming in the fountain until you correct the issue your coating supplier should be able to send you a small quantity of an anti-foaming agent.....just takes a tiny amount. Has the anilox roller been changed recently?

[Michel Walinga]

Try pulling out the return pipe, the return pipe should be higher than the infeed pipe.
Dous your blade chamber has a feed in from the middle, and do you have it on higher speeds? Try to let the coating float into the barrel (on a alluminum pate or so) this wil let out the air and not pump it around...