Ink Buildup on Plate

JudP

Well-known member
Ran into something last night I've never seen before. Running a large magazine on our Sunday 2000 (177,000 run) and after about 25,000 impressions I am getting a pretty solid ink build up on the yellow unit. It's happening both top and bottom. Took the plates off and I was shocked to see about a 2mm thick build up. It is definitely effecting print quality and happening on both top and bottom.

Was down for about two hours troubleshooting - checked conductivity, pH, temperature of fountain solution, temp of water in the pan, plate temp, blanket temp, roller temps, settings of rollers all correct. All normal in the unit!

Checked with Prepress and nothing changed there...

Just switched over ink and am draining the pipes now (ink totes are about 100 feet away from the press). Could be bad ink??

Anyone see anything like this before?

Jud
 
Checked with Prepress and nothing changed there...

I can't picture a 2mm thick layer actually building up (not that I don't believe you!)... the pressures must be huge! However, I think you can safely rule out plates/prepress from causing this issue. If you think about it, once there's a layer of ink on the plate, the plate is no longer directly interacting with the ink and can't cause thicker buildup on top of that ink by itself. There has to be something in the ink causing this, possibly with contributing factors in your ink train.

Kevin.
 
Piling

Piling

It's not piling, is it? Pigment staying behind on plate and not transferring with the vehicle. The sort of thing we get on sheetfed, esp on blankets on long runs when the press gets hot.
 
I can't picture a 2mm thick layer actually building up (not that I don't believe you!)... the pressures must be huge! However, I think you can safely rule out plates/prepress from causing this issue. If you think about it, once there's a layer of ink on the plate, the plate is no longer directly interacting with the ink and can't cause thicker buildup on top of that ink by itself. There has to be something in the ink causing this, possibly with contributing factors in your ink train.

Kevin.

I know! I was shocked to see the plate. Checked plate to blanket and blanket to blanket squeezes and they are normal! Checked ink and water forms too. Nothing seems out with the press. I can't figure it out yet!

Jud
 
It's not piling, is it? Pigment staying behind on plate and not transferring with the vehicle. The sort of thing we get on sheetfed, esp on blankets on long runs when the press gets hot.

It could be piling but temperatures are normal!

Jud
 
Downstream Piling

Downstream Piling

Hello JudP

1) Downstream piling is characterised by Ink Build-Up within the Image Areas on subsequent units after printing. KCMY

2) Cause: often poor Ink/Water Balance which leads to waterlogged ink with poor transfer properties.

3) Paper Coating: Moisture Resistance Properties.

PDFs - JudP read Diagnosis No. 13 also No.6 TVI diagnosis


Regards, Alois
 

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mmmmmmmm

mmmmmmmm

JupD


2mm equals 0.78 thousands of an inch !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

A litho plate thickness is 0.03 (012) thou

So are you printing by Letterpress NOW ?????

Regards, Alois
 
Last edited:
JupD


2mm equals 0.78 thousands of an inch !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

A litho plate thickness is 0.03 (012) thou

So are you printing by Letterpress NOW ?????

Regards, Alois

Hey Alois,

I know!!!! It's utterly bizarre!! I'll try and post some pics as in my almost 20 years in printing now I have NEVER seen anything like this. The plates look like a thermography print!!

Regards your last post, I definitely don't think it's piling from the earlier units as it is not building up on the blanket and it is only clearly yellow ink on the plate.

Just got a new tote of yellow ink here from our supplier so we will see if it really is due to bad ink...

Best, Jud
 
Yes I am. Ink is Hostmann Stinburg or something like that.

Imagine that! Our ink is from Hostmann as well and I had the tech rep in here the other day and he did confirm that it was bad ink. Apparently they were having a problem with the yellow formulation however it wasn't wide spread but enough of a problem to warrant a change in the formulation so that it wasn't picking up so much water. After three replacement totes of ink, we finally got the "new" formulation of ink and problem solved! Frustrating beyond belief...

Jud
 
The 'problem' is likely PCC (precipitated calcium carbonate). We recently had an ink supplier comment on this problem with our ink. They pointed to the paper as the source, but...well. We changed lots and it went away. Use your imagination.

Companies are starting to add strange products to their inks to keep costs down. I'd suggest that next itme it happens, pop of the plate and cut out a piece for you ink supplier to actually look at. Or, get it analyzed yourself (you could try dissolving the build up in water to see if it actually is PCC which is water soluble).

Anyways, hope this stops happening to all of us.

The printing industry is blowing apart at the seams.
 
(you could try dissolving the build up in water to see if it actually is PCC which is water soluble).

According to the Merck Chemical Index, calcium carbonate is 'practically insoluble in water'. The fact that PPC is precipitated rather than ground up from rocks does not mean it is not still calcium carbonate. PPC is often not pure however, and may contain a certain (small) amount of unassociated calcium ions, but it is unlikely that anyone would have enough soluble calcium in their system to cause problems without their primary complaint being roller stripping.
 
Man it barley came of scrubbing with MRC. I can guarantee water would not touch this build up.

If you have a calcium build-up, it should rub right off with a product like Lime-Away or C-L-R, products designed and sold (in the US and Canada) to remove lime scale (another name for a calcium build-up). Be careful though, these products are not good for rubber printing rollers and should be used with care. If a deposit does not come right off when using either of these products, the deposit is most likely not calcium. Solvents, no matter how strong will not have much effect on a calcium deposit.

One rule of thumb for calcium issues; calcium deposits are water loving and ink will not stick to them in the presence of fountain solution. Blinding and stripping may be calcium related, ink sticking to things it shouldn't stick to is caused by something else.
 
bad ink.

bad ink.

Ran into something last night I've never seen before. Running a large magazine on our Sunday 2000 (177,000 run) and after about 25,000 impressions I am getting a pretty solid ink build up on the yellow unit. It's happening both top and bottom. Took the plates off and I was shocked to see about a 2mm thick build up. It is definitely effecting print quality and happening on both top and bottom.

Was down for about two hours troubleshooting - checked conductivity, pH, temperature of fountain solution, temp of water in the pan, plate temp, blanket temp, roller temps, settings of rollers all correct. All normal in the unit!

Checked with Prepress and nothing changed there...

Just switched over ink and am draining the pipes now (ink totes are about 100 feet away from the press). Could be bad ink??

Anyone see anything like this before?

Jud

Hi jud,i have seen this before i it is bad ink.Sometimes the tack in the ink will change either
it will get loose or thicker.
good luck,victor
 

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