Heidelberg hickey problem

I’m having trouble with hickeys (hickies?) today and cannot for the life of me figure out where they’re coming from. Press is a 10x15 Heidelberg. The ink train was clean and I’m using new ink. It’s never happened to me before except on this particular paper (Colorplan 600gsm), so I don’t know if that has anything to do with it. I’m doing a second run of this particular job. The first time I ran it, I had some minor hickey issues and just dealt with it, but this time they’re everywhere. Could it be coming from the air blast at the feed table? I used some Q-tips with mineral spirits to try to clean them out but that doesn’t seem to be alleviating the issue. Help!

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Jonsel,
If you haven’t overcome your hickey problem yet here are some things to look for in following hickies.

Typically hickies fall into three categories. A) Ink skins, B) pick outs from the paper and C) slitter or cutter dust.

Most importantly, what is the shape of the hickey? If you look at the hickey under a loop you will typically find one of three shapes.

An ink skin is a very irregular shape with straight edges. I would stick to the ink roller or the plate and cause a donut with the shape of the ink skin in the middle. If it is an ink skin that is causing it, wash up and make sure the ink is fresh and clean.

A paper pick out will be a very irregular shape but show traces of fiber when viewed under a loop. You would see sort of a “hairy” spot. If it is a pick out, your ink tack may be too high for the sheet and pulling fiber out of the sheet.
Usually you can trace this back to the actual sheet(s) that have the fiber picked out of them and this will be proof that that was the issue. However, your ink could be fine but the sheet could be defective, either not having enough or no sizing at all. I do not know if Coloradan is sized, but I’m guessing it is used for offset, in which case it definitely would be. You could try turning the sheet over to see if both sides pick. On a sheet like that it could have very different characteristics side to side.

If it is cutter or slitter dust. The hickey will be irregular but more like a trapezoid with some long (relative to its size) and very straight edges. If this is the case you can try fanning the sheets, dusting them with a microfiber cloth, but more importantly rechecking the sharpness of you blade as well as your other cutting procedures. Typically you would want to take a back trim on every cut, as the edge of the lift on the front of the blade will be more ragged.

Of course too much pressure, and with 600gsm, there must be a lot, could in itself be fracturing the sheet and causing some fiber to back up into your ink train.

Keep us posted,
Steve Varvaro

Jonsel, you are probably correct in your thinking that it is coming from the air blast.

If you are finding this all along the grip end of the sheet and into the sheet a bit it is probably from the air blast being so great due to the weight of the stock you are running and the fact that you have oil in the air lines. I have a windmill that will do the same thing if I push too much air through it to separate the stock I am running.

I believe it to be from over oiling the air pump piston felt ring….what ever the Heidelberg technical name is for that part.

If you take a stack of the stock you just ran and look at the end of the sheet pile that is your grip end, you will probably see it even more when it is stacked in a pile like such.

Thanks for the suggestions.

Here’s a link to a few photos, all from the same sheet. Maybe this will give you some more clues. Hickeys are on the sides, in the center. They’re everywhere.

Could heat/humidity be a cause? It’s much hotter now than it was back in late April.

http://www.voteforletterpress.com/images/hickey.jpg

(And yes, there’s a ghosting issue which also wasn’t present the first time, but I’m focusing on the hickeys first.)

Steve, it’s not cutter dust, at least from my end. The sheets were supplied pre-cut and back-trimmed by the manufacturer.

I think those are dried ink chips which are getting stuck on your plate.

The ink was purchased from VanSon in April. It’s not even skinned over yet (oil-base). Could there be dried ink underneath the ink fountain that’s getting pulled into the train? Maybe I should ink up without the fountain to at least see if the hickeys are still there.

Jonsel,
I can’t comment on Rubicon’s suggestion about over oiling.
Not sure if he is suggesting that felt particles are being sprayed into you delivery pile. It is hard to tell from the photos but based on the shape they look more like the round hickies you would get from fiber. I believe ink skins/chips would have a harder edge inside the donut.
Maybe a high pressure in air blast is creating a dust storm at the feed board. Is everything as clean as can be. Is there any indication of loose particles in or around the feed board?
If the sheet is coming apart you should be able to find voids in previously printed sheets where the “pick-out” occurred. If it is ink skins they should be somewhat visible on the ink train rollers.
s
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What’s the best way to clean the air blast/feed board area? There’s lots of little nooks and crannies and I figure I should just make it look as sparkling as possible. There’s lots of dust in there. Again, this is the only job where I have this problem, so I’m not sure why it’s just this one.

Could this be a void from a fiber pick-out in the lower left of this photo?

http://www.voteforletterpress.com/images/hickey2.jpg

I’m not seeing any more of them, although I haven’t gone through each sheet. It’s pretty darned small.

If this is pulling fibers from the sheet, what’s the solution? The job is two-sided, so I can’t just switch sides.

I think my plan of action for tomorrow is to ink up and run a few prints on Lettra and Reich Savoy and see if the hickeys are still a problem. That should eliminate (or possibly confirm) the Colorplan paper as the culprit. I’d put these on my SP-20 if it wasn’t 2/2 and 1,500 qty.

It looks like picking from too much ink tack, especially if the problem limits itself to one particular brand of paper. You can either cut the tack with reducer, or put in some binding varnish to loosen up the ink (not too much or the color will shift lighter).

Looks like ink to mee wash the machine a couple of times with yellow ink querosene and water to drie out (water is your best shot to eliminate paper residual) it is easier to notice the leveling and acumulated dirt or dried ink. Did you use antioffset spray on your first run?

Picking. Paper picking. This will disappear when the job does! Maybe a little thinning of the ink, and run the machine dead slow.

After seeing pics of the problem I retract my original suggestion as it doesn’t look like the problem I visioned at first.

Lot’s of good suggestions here so hope you get it figured out.

Good Luck!

How much tack reducer should I put in? Figure a couple full gobs of ink on the palette knife (precise term, eh?). A couple drops? 50/50? The ink is pretty loose, not stiff at all. Not sure if that’s a measure of tack or not.

Thanks to everyone chiming in. The help is much appreciated!

I don’t know what it’s like in a paper factory but I’m convinced that some paper goes through a special dust and dirt layering room such that most of the sheets in the ream are covered with random bits of stuff. I have had days when I’ll be running several jobs in the same color and everything has gone fine until I start with some new stock and suddenly the image is covered with fisheyes just like these and the ink on the ink disk is full of small dust particles. I clean off the ink and start over paying close attention to the problem but it comes back no matter what I do until the end of that job. My idea for this would be to aim an air blast at the surface of each sheet as it is exposed in the pile to blow the dust away from the ink/press.

Just ran off a few sheets. I’m not using the ink train at all, just inking the drum and form rollers.

http://www.voteforletterpress.com/images/hickey3.jpg

The image on the left is 1 sheet, and the one on the right is the subsequently fed sheet. It’s small, but the void is in the same exact place as the hickey on the next sheet. Seems like paper picking, yes?

Just ran some sheets of Lettra through and had definite paper picking, so not just the Colorplan. I guess that points at the ink being the source of the problem?

Do art supply stores sell tack reducer of any kind? I need to get this thing on press today.

The only thing I can think of which is readily available and non-toxic, might be a drop or two of non-scented baby oil, but I haven’t tried it personally. It probably won’t take more than literally a drop or two, and that tiny bit, when spread out over the whole job, will be a pretty small amount on each sheet and isn’t likely to adversely affect ink drying, etc. I would try mixing one drop into a small amount of ink on a glass surface first, just to make sure it goes into the ink and thins it as desired.

Printing inks are made with “oils” which absorb into the sheet anyway, so this is not a whole new thing you would be doing to the ink.

One thing Bruce cpd said above, about his ink disc being covered with small particles from the paper, makes me think of a point which no one has mentioned yet. That point is, that hickeys tend to work back through the ink train and even can end up in the fountain. That is because the ink is the most stiff and tacky in the fountain, and as it goes through the ink train and is worked up by the rollers, it becomes less and less tacky, reaching the plate where it is the least tacky. If the ink on the plate picks up a hickey, the slightly more tacky ink on the form rollers can pull the hickey off the plate onto the form rollers. Then the slightly more tacky ink on the distributing rollers will pull the hickey off the form rollers onto the distributing rollers. Finally the even more tacky ink on the metal fountain roller will pull the hickey off the distributing rollers, onto the metal fountain roller, and from there it will go into the fountain. It sounds incredible, but that’s what can happen.

For this reason, if you are having a hickey problem you probably shouldn’t save the leftover ink after the job is done, because that ink could have a lot of hickeys in it.

I ran another test using an old can of Rubine Red and no issues with it. A little bit of picking, but no resulting hickeys. My feeling is that there’s something in this ink that’s causing it. These hickeys happened with both colors on this job, so looks like I need to replace both cans.

Ramblings from afar, that do not seem to have been touched on this far.
Is it remotely possible that SILICONE Polish has contaminated the system at some point.
It appears to be very well documented that Silicone polish or derivatives Repulse EVERYTHING, which is the nature of the product,
Possibility and apologies for rubbish.

Addendum + As an extra experiment to possibly show, “what” is migrating from “where” or vice versa, with a china clay coated Art Paper and by hand of course, put one around the rollers, (happens on the run occasionally anyway)
With no forme in and when the rollers are on the downward stroke peel the sheet off, will give a good readout of the face and obverse of what ink is transferring (or otherwise) and what is being carried with it.??

pardon if i missed this one in the above possible causes.
it looks to me like foreign particulate, coming from someplace. Does the back of the sheet show any sign of increased pressure right at the center dot of the hickie? If so, it is either in the stock before impression, (this would have it moving around, changing locations on your image). or, it is introduced to your forme from someplace, being inked, and if staying in the same place on the image, is stuck to the forme. In a bad case, cleaning the forme will help for a short number of cycles. then it reappears.
these can be frustrating, but i try to change just one thing at a time. then i can tell what actually solved the issue.Unless time or stock qty is an issue, then change as much as you can think of, all at once.

I finally was able to run the first color today with the new ink I ordered. No hickeys at all. Whew. Let’s hope the second color works the same.

It is not unknown for ink companies to supply inks with defects, and this looks like an example of that.

It would be interesting to do a few drawdowns of the first ink which has the hickeys, straight out of the can, using varying amounts of pressure on the drawdown blade. If you can make the hickeys show up, it would be good evidence to show the ink company what the defects are, to get a credit for that ink. That way you eliminate the press as a variable and the ink company can’t blame it on something you did on press.

My next step is to go back to VanSon and try to get my money back. We’ll see how well that goes, but I tested almost every variable, I believe, to isolate the issue. The nice thing about my other ink manufacturer is that I can talk to the lab guys who do the mixing, so I could tell them about the fiber picking and they formulated the new ink accordingly. The only problem is the minimum order is a 2 lb. can, so it gets expensive.