piling on webpress

[ar17]

we are encountering piling issues on our web printing which costs us expensive downtime. any help or suggestion how to reduce or totally eliminate this issue. we have an m600 that runs on coated stock and we have to clean the blanket every now and then to fix the piling that accumulated... thank you for any input...


ar

 

[Paultheprinter]

There can be many reasons for piling, most of which are not fully understood at present, there is a gatf study on piling around on the web, i have a copy somewhere which i found using google. Most of these issues were due to incompatability between ink fount and paper, i think from memory all of these variables played equal parts in most cases. The report stated that piling mostly started during the make ready procedures and continued form there to get worse, i assume you run heatset inks ? so my input with cold set inks would only hinder your progress.

Paul

The report was called "heatset web offset performance study" by dr mark bohan

 

[Bob Peterson]

You didn't mention whether or not it was piling on the blanket or the plate. I will assume that it is piling on the blanket as this is the most common. If you can answer a few questions I may be able to provide you with some direction.

What grade of coated paper are you primarily running?
What types of coverage do you typically run?
Do you see piling on every type of coverage?
Are you running a one step etch?
Are adding a anti-piling additive to your fountain solution? If so how much.
How often is the complete dampening system completely drained, flushed, and refilled?

If you would like to speak over the phone drop me a PM with your number and I will give you a call.

Regards,
Bob

 

[jlind]

Piling On Web Press

Piling On Web Press

That GATF study was on a 38 inch MAN Roland heat set web. The issue started with looking at piling in the light coverage while printing stochastic. It was always non-image area piling. The final results of the study were pretty statistical and no hard answers. Piling just IS on a high speed press and you have to clean the blankets after every couple rolls if you want to produce consistent quality without mottle and wormy patterns. On the other hand, I worked on a project with stochastic printing and the same press and ink consumption studies. It is pretty well known that stochastic printing and any high screen ruling printing uses less ink. When I made a presentation to a group of WalMart insert printers, some experienced piling and some never saw any piling. Now this was cold set on improved news, maybe. WalMart insists on stochastic printing for quality and INK SAVINGS. This anecdotal evidence suggests that you can have the right combination of ink and water and the blanket will be flushed and printed clean. The non-image area piling has to begin with ink particles floating in the fountain solution and building up on the blanket. The blanket roughness could be a factor, or the absorptivity of the newsprint to take the water-ink fluid away faster than a coated paper sheet, maybe the roughness of the newsprint scrubbing the blanket in the nip versus a smooth coated paper. Perhaps more information than you wanted, but take what you want and leave the rest, as they say.

John Lind
Cranberry Township, PA
724-776-4718

 

[keldrewett]

Hi. The problem is caused by the fountain solution.
You need a quality product with high speed wetting agents that act as a lubricant to stop the piling.
You dont state what product you are using or what the in coming water quality is like.
Post up again and i'll give you some tips.
If you are in or near australia i can help directtly.

 

[Darlek]

we are encountering piling issues on our web printing which costs us expensive downtime. any help or suggestion how to reduce or totally eliminate this issue. we have an m600 that runs on coated stock and we have to clean the blanket every now and then to fix the piling that accumulated... thank you for any input...


ar

I encountered this problem many times when I was running heatset presses. It was traced once to a poor setting on a roller. The roller was in the train of rollers NOT a form roller. It was so tight that it gave the effect of ink surging and in turn caused piling. If it is only on one printing couple then this is for sure the fault. If it is on all printing couples then look at how clean your fount system is running. Blanket height can also create this, if the blanket is to low it will give a gradual build up becauuse you are getting a poor transfer of image. I found this however more of a problem on NON coated stocks. If you can under pack try an extra 1thou to see if it makes the difference.Finally on a Komori press I ran with alcohol damping we just did not carry enought damp this caused piling. Try running the damp from the start @ 10% higher.

 

[jlind]

Darlek:
I saw that roller setting issue once on a 38 inch MAN Roland heatset web. The form roller was too tightly set on one side of the press, on one unit, and there was piling on that side of the blanket. Reset the rollers, piling gone.

John Lind
Cranberry Township, PA
724-776-4718

 

[keldrewett]

Its the fount!!

 

[bikozak]

Troubleshooting piling

Troubleshooting piling

we are encountering piling issues on our web printing which costs us expensive downtime. any help or suggestion how to reduce or totally eliminate this issue. we have an m600 that runs on coated stock and we have to clean the blanket every now and then to fix the piling that accumulated... thank you for any input...


ar

I also worked on an m600 for 3 years. I must say, it makes little difference though what type of press you work on. There are some questions you should answer first
1.) Is it paper or ink piling?
2.) How long does it take to occur?
3.) Is it only on one color or all?
4.) What type of fountain solution / ink do you use?
That would be a good start. There are lots of troubleshooting guides out there.
Try this one:
Troubleshooting Piling
We've found with good chemistry we can go 90,000 before washing blankets.

 

[BeauchampT]

One other thing as well - take the time to figure out what ink is piling; my plant has had some tack issues so that you have black ink piling in the other print units. The key was running in a way that controlled the black, not the other units

 

[Bloodsaler]

First check your file be converted by a low ink coverage ICC/It`s important!If you convert by a sheetfeed icc,it may occur piling~
And of course,there`s many other reasons

 

[Blanket guy]

Has the piling always been there? non piling additive will help, but may not be the solution. Can you provide some more detail? ie. blanket packing, fountain solution conductivity, RO water? etc.

 

[SHELBY]

I also worked on an m600 for 3 years. I must say, it makes little difference though what type of press you work on. There are some questions you should answer first
1.) Is it paper or ink piling?
2.) How long does it take to occur?
3.) Is it only on one color or all?
4.) What type of fountain solution / ink do you use?
That would be a good start. There are lots of troubleshooting guides out there.
Try this one:
Troubleshooting Piling
We've found with good chemistry we can go 90,000 before washing blankets.

I had to read this 3 times, 90,000??? man are you washing these on the run??? if all your hitting is 90 gran on coated or even uncoated............time to call 911

 

[HecTiK]

Ive hit 175k on 40# grade 5 gloss, not washing blankets at all. Would have tried for more if the splice wouldnt have jammed the folder... I'd say regularly on said paper I can hit 100k to 140k, but sometimes as low at 35k.

 

[ronson]

I run allso m600 and had a same problem few years ago, I changed everything, but most significant contributors on removing the problem, was blankets and cylinder pressures