Some water related problems faced and possible solutions

[engin]

1st Problem faced: KOMORI Lıthrome 40 S, the problem is that on cyan inking rollers, the metal surface was bare and metal surface of the roller from half like cut with a knife,there was no cyan ink on half of the roller. When I checked that, the printer was using a soft drinking water.In water system with the conductivity of about 100 microsiemens. When we added some hardener then the problem is overed. If you say why only cyan unit, then I can say that as KOMORI users know that the inking rollers have copper on the surfaces and the cyan pigment (Pigment Blue 15:3) is made up of from the raw material cupperpthalocyanine. Both have cupper so this cupper is creating this strange problem when inner water is soft. If the reverse osmosis system there and by any how if hardener not added to the system the same problem could happen for KOMORI press.

2nd problem faced: When the heat set printer called me on saturday, he told me that all the balankets are piling up with water dust after 10000 copies which is a very short run for heat set printing and the subsrate was a coated LWC paper. When I checked the press, it was true all the blankets were piled up. After investigating, I found that from the reverse osmosis system, the processed water was coming into the technotrans system around 100-120 microsiemens, strangly that there was a control chart there and the operator was writing there the same numbers by declaning from 280-300 to 100-120. When I asked them they had this problem for a while. The hardener feeding pump was not working efficiently. The possible cause is that since the water is not rich with calcium so it is very agressive now and needs calcium to be satisfied to reach 300 micrrsiemens so looks for calcium and the main calcium source in the system is the paper surface. Whatever the paper type is, it pulls the paper surface and takes with it and excessive paper parts accumulates on the blanket wherever it is.

3rd problem faced:When a 2 press printing was done, they told me that the red areas are fluactuating and decreasing the red shade in some areas I saw that they were removing by separating with hand bad ones.I checked and found that the incoming water was tap water from ground and it was 2000 microsiemens,no reverse osmosis. The possible cause is that the excessive calcium which comes from tap water are accumulating on the inking rollers and especially on magenta (Pigment Red 57:1) unit the problem is a disaster. Why? since the magenta pigment is made up of calcium salt so that like pulls like then the calcium from the water comes there and pulls water to the surface of the rollers and rollers not transfer the ink anymore successively where calcium deposited.

Water treatment is so importatnt, it should have the hardness within certain limits. Hardeners by the way, should be added 0,5 % generally, 0,1 % hardener addes up to the conductivity about 50 microsiemens, one should consider that and treated water depending on the system effectivity up to maximum 50 microsiemens conductivity water terats so the 250 microsiemens comes out from hardener and maximum 50 from treated water tottally in generaly 300 microsiemens.

Best regards,

Engin

 

[Dan Roll]

There are some areas in the U.S. where the conductivity of the water is close to zero while other areas have water Europeans would consider to be of moderate hardness. I have never observed any trend in these areas that would indicate soft water is worse or better for printing than harder water. Many American fountain solutions contain enough magnesium salt to bring the water hardness well above ten grains per gallon, but solutions not containing magnesium often outperform them. Calcium has been portrayed to American printers as the root of all evil, not least by those selling RO units, so the idea of buying calcium salts and then adding them to the water makes many printers suspicious.
My question is if water hardness is so important, why do its proponents not include these salts in their fountain solutions instead of charging extra for them as an additive?

 

[engin]

There are some areas in the U.S. where the conductivity of the water is close to zero while other areas have water Europeans would consider to be of moderate hardness. I have never observed any trend in these areas that would indicate soft water is worse or better for printing than harder water. Many American fountain solutions contain enough magnesium salt to bring the water hardness well above ten grains per gallon, but solutions not containing magnesium often outperform them. Calcium has been portrayed to American printers as the root of all evil, not least by those selling RO units, so the idea of buying calcium salts and then adding them to the water makes many printers suspicious.
My question is if water hardness is so important, why do its proponents not include these salts in their fountain solutions instead of charging extra for them as an additive?

Dear Dan,
In Europe, fount solutions are not so acidic as you have in US.
(Nowadays, some vendors tend to offer acidic F' in my region but not very common.)
The main issue then is to keep water hardness under control since FS do not help at that side. Water treatment ( most commonly used in newspapers then sheetfed printers started to have in Europe) is very importatnt, controlly reduce the water hardness to zero then increase up to 300 microsiemens.
One customer asked us as what you suggested, to add hardener into the fount solution then what happened sedimentation occured. How we solved, instead of calcium hardener, we added magnesium hardener into the FS as 1/5 ratio and tell to the customer to use 3 % of this mixture.
But again,all the rest newspaper printers want separate FS and hardener.

regards,

engin