ink buildup on coating blanket

[Tashi D]

Hi, I run a Heidelberg speedmaster 6c with coater and extended delivery. Recently seeing ink buildup on coater blanket when running satin coating. Not so much, but still evident with gloss. Does anyone have thoughts about the cause of this? I think its a chemical problem, as packing and anilox nip settings haven't changed. Maybe the cells are clogged on the anilox? Thanks in advance
Tashi D

 

[Freeman A.Gain]

Definitely sounds like your coating is starving. Could be clogged cells.

 

[RJ Litho]

Tashi, if this is a two roll coater try heavy viscosity coating around 25 seconds with a # 3 zuhn
cup. All so ,go in to your console depending on year you should be able to set your coating profile . high, medium or low this is based on viscosity , set a cure based on this . very similar to a dampening curve. We have two Heidelbergs and have very good success . if you have chambered doctor blade high viscosity will also work well . Depending on your cell volume this to little coating may cause ink to build . We use a 200 lPI 60 DEGREE 9-10 BCM . Set coating to strip off a couple of sheets . Start up with coating coming on two revolutions before print .

RJ

 

[Tashi D]

Thanks, I'll search the console files for the coater profile adjustment. We have a cleaning product for the analox that we use with ammonia, but I wonder if anyone has alternatives for scrubbing out the cells?

 

[REYES1377]

Thanks, I'll search the console files for the coater profile adjustment. We have a cleaning product for the analox that we use with ammonia, but I wonder if anyone has alternatives for scrubbing out the cells?

Sodium blast one time per year. Have you done this ever to this roll?

 

[Freeman A.Gain]

There is a product line from a company called Recyl

RECYL - Ink system cleaning - Cleaning products for the printing industry - Cleaning machines for the printing industry

Works top notch!

 

[Tashi D]

We have two anilox rollers, sent one out for cleaniong about a year ago when we were experimenting with "soft touch", then had the spare cleaned when we switched them out. My basic settings file does not allow for changes to the coater profile. We're also getting horizontal streaks that our mechanic says may be due to a faulty clutch?? We probably run over 300 gallons a month of coating through this thing, sometime nonstop for a week. I need to convince my super to let me switch analox rollers.

 

[RJ Litho]

coating roller

coating roller

What is your spec are your rollers and what viscosity are you running ?

RJ

 

[jms]

i had the same problem i could not get more than 1500 impressions before ink started building on the blanket i fixed the problem by wiping it with clorox before starting the run. i have gotten 100,000 impressions and no signs of ink build up.

 

[Tashi D]

Good morning,
I don't know the cell count on our rollers, but we keep our viscosity around 18-20. I think its a no.3 cup we're using. I've been told I could go as low as 14, but have not. Every aspect of this industry has layers upon layers of technical detail, and simply coating a job is no different. Friday we coated a full coverage rich black job and got the alligator-skin effect on the coating that I haven't seen in years. My question today is what do you all think causes this? I remember dealing with this long ago by changing the dryer temp, or viscosity. On Friday we switched to a barrell of "low curl" gloss coating and the problem dissappeared. In general I'd like to learn more about this problem. Thanks