Ink Buildup on Plate

[JudP]

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

[Kevin@Kodak]

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.

[jamfor]

Same think happened to me a few weeks ago. They said it was bad ink

[Leedsprinter]

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.

[JudP]

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

[JudP]

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

[JudP]

Same think happened to me a few weeks ago. They said it was bad ink

Hi Jamfor,

I have my ink supplier involved now. Are you running a heatset web? What ink company do you use?

Jud

[Alois Senefelder]

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

[Alois Senefelder]

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

[JudP]

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