crooked scoring on folder

[Cameron]

Hello everyone,

I was hoping for a little help with something. We used to score everything with a Letterpress but its getting quite old, and I wasnt happy with the scoring quality. (Plus I find it slow to set up and run). So we invested in two things.. a tabletop Morgana for small run and a heidelburg scoring wheel for our baum folder.

Anyway, the score wheel for the folder is great for any kind of substantial run, we are having no cracking issues that I am concerned about, but we are having serious consistency issues. The sheets are going horribly crooked, some are good, but a LOT are bad. It seems the thicker we go with stock the worse it is. The stock we are deadlocked on right now is just a 100 lb. Cougar Cover. That is basically as thick as we go anyway.

Another side issue which isnt too much of one is that the folder curls the sheet quite a bit after it goes through.. does anyone know if thats just the way it is, or if that doesnt sound right?

Any help or advice at all would be really really appreciated.

Thanks,
Cameron

 

[Al Ferrari]

Welcome to these forums Cameron,

The crooked scoring problem due either to

1. Uneven pressures somewhere in the roller train or exit shafts so that one side is being driven harder/faster than the other,

2. End play in one or more of the rollers or exit shafts, or

3. Unevenly set deflectors on the unit doing the scoring.

Do you have an experienced folder operator? The first cause is common with beginners, The second cause can happen from time to time regardless of level of experience.

What size and age is this Baum folder? For curiosity's sake, can you say more about this Heidelberg scoring wheel for your baum folder. I was not aware that they supplied parts for Baum folders.

You might also look into wet scoring in conjunction with blade scoring. I use it with great success. Try a Google search for it.

The curling problem is very common for cover stock, especially if the grain of the stock is running perpendicular to the rollers. This has nothing to do with the scoring. The only solution, if needed, is to manually work the curl out before further processing.

Al

 

[Cameron]

Hi Al, thanks so much for the welcome and the response.

I gave a quick look at the wet scoring and will look more later.. very interesting!

The folder (forgive me because I havent really looked that close in a long time, I should be much more aware of exactly what we are using but I am not 100%) looks exactly like the Baum 2015. I downloaded the manual yesterday because as far as I know, there has never been any excessive training on it. The usual operator for the machine never adjusts the air levels for different stocks etc as per the manual. I would estimate the machine is around 10 years old or thereabouts. And just in case your next question would be what kind of service/maintenance has it had... I would say minimal to none. The machine looks to be in very good condition, but its possible that there are things that should be replaced that we just aren't aware of. Is that something that we should be looking at? (A quick estimate on throughput I would say that we probably put through about 100,000 a month)

One thing I am uncertain of, is how critical the exit tires are on the exit shafts?
I know the operator does not consider their placement or use a big deal.

The heidelberg score wheel, never had a name like the others I have read about on this site (I wish i knew about this site a long time ago, or had done more internet searching). Basically, The male part has two seperate grooves for seperate thicknesses of rubber score inserts, and the female part if I recall correctly has 2 or 3 female grooves to match up with.

Thats no problem about the curl, I just wasnt sure if it was something we just didn't know how to correct.

 

[Cameron]

SORRY! I was just double checking, and I guess i was wrong, the stahl folders look exactly the same as well, so it would make much more sence that it is a stahl not a baum, my mistake!!

 

[Al Ferrari]

You write:

"One thing I am uncertain of, is how critical the exit tires are on the exit shafts?
I know the operator does not consider their placement or use a big deal."

This could be the problem right here! These wheels are intended to CONTROL the stock as it travels out from the exit shafts on which may be mounted slitting, perforating, and or scoring elements. So, is their role important? Does a bear sh...t in the woods? You need a change in his attitude or a change of operator. (I hope you have been fair in his portrayal, otherwise I wish him no ill.) If these wheels are not well centered above the exit shaft, they may be causing the problem.

Try walking a sheet trough the folder slowly and check to see where it starts to go crooked. Does it go into the rollers square? Can you notice one side leading as it comes out of the fold rollers? What about as it travels through the exit shafts under the poorly placed exit tires?

Your description of the male/female score wheels make it seem similar to the Technifold products. Good stuff!

Let us know how you make out with these suggestions.

Al

EDIT: After checking the Stahl version on our floor this morning, I have to retract some of my comments made above. That particular size folder DOES NOT have the pull out wheels I referred to as serving the purpose of controlling the stock after the exit shafts. My apologies to your operator. He is correct that the placement of the tires on the exit shafts are not critical as long as there are some on each side of the score collars. I hardly ever run that particular machine, so I spoke out of turn. My experience is with the larger Stahls.

All my other comments apply, especially those regarding evenness of pressure settings on the rollers and the exit shafts, and assuring that there is no end play on any of these rollers or shafts.

 

[Al Ferrari]

I checked for Baum 2015 at: http://www.pitneybowes.ie/PDF/ProductionMail/Brochures/Peripherals/Folders/Baum2015.pdf and that looks just like one of the Stahl folders on our floor. It may be a case of one or the other company re-marketing a rebranded product.

Al

 

[Cameron]

Hey Al, it definitely is a stahl, I went in this morning to double check and try to get this job to feed properly. I adjusted a few things as per the manual, as well as properly positioned the exit wheels and voila, it worked PERFECTLY. I only ran a small quantity just to test it out, but we'll try to run the full job tomorrow and make sure it stays nice and consistant through the run. Thank you so much for helping out!! Ps the operator has been with us and a real asset for probably 40 years, so he is much more used to scoring on the letterpress. I cut him a little slack when it come to progressing, he deserves it! You were a great help though thank you very much Al!!!

 

[ondemandbindery]

A couple of things can do this. Check your sheet registration in the side guide. This has been the NO.1 problem I have run across with something like this with all brands of machines. The guide gets a groove in it over time. Second is roller pressure. When you say inconsistent is it on both ends of the sheet? If not is it the lead edge or tail? And lastly, pullout wheels can be a problem child. Stagger them so none are over top of each other. If the pullouts are running a different speed than the scoring wheel that can cause this also. If you are experiencing tailoff this can be a typical problem when scoring with the knife shafts. Experiement but there is no gaurantee to get 100% consistency. The wet score is definitely an option. If your sideguide is in good shape you can get very consistent scoring this way and less cracking. Check this stuff and report back.

 

[Cameron]

We posted at about the same time ondemandbindery thanks for all the helpful tips as well! The side guide seems to need small adjustments here and there but not too bad.. what I did that seems to work much better as per the earlier suggestions by Al, and the manual, was to adjust the steel marbles in the track so there were a couple more steel ones at the beginning..we were tightening the side guide right up to the stock but the manual says to keep it about 1/8 or so away from the edge so I backed off a bit, I adjusted the air to the manual's guide for that width.. an lastly set the exit rollers so there were a couple on each side of the score. It really seems to make it work.. hopefully all stays well tomorrow. For now I can enjoy whats left of my long weekend!

thanks!!!

 

[Al Ferrari]

Use of proper side guide balls is also important

Use of proper side guide balls is also important

ondemandbindery's post reminds me that I failed to mention the importance of the balls on the register table. When running heavy stock, heavy metal balls should be used to insure that the sheet is pulling over to the guide. Also, there is a slit at the end of the side guide just before the sheet enters the first fold roller pair that allows the operator to "view" the sheet travel. Watch as several sheets go by this opening and insure that the full length of the sheet is hugging the guide.

I goes without saying that the guide should be square to the rollers.

Al

 

[ondemandbindery]

ondemandbindery's post reminds me that I failed to mention the importance of the balls on the register table. When running heavy stock, heavy metal balls should be used to insure that the sheet is pulling over to the guide. Also, there is a slit at the end of the side guide just before the sheet enters the first fold roller pair that allows the operator to "view" the sheet travel. Watch as several sheets go by this opening and insure that the full length of the sheet is hugging the guide.

I goes without saying that the guide should be square to the rollers.

Al

Something to look out for is a used econocrease unit. What that does is eliminate your 2 top plates and it attaches in that area. What makes it work really well is your sheet will only go through the #1 roller and then into the creasing unit. I suspect they are plentiful. Either way good news you got your problem resolved.

 

[LoganBlade]

1. set all rollers to sheet. Score roller as well
2. set side guide square according to machine.
3. take pressure off roller 2, 3, and 4
4. send down sample. if square you are good.
5. if not add pressure equally on 2, 3, and 4 on the longer side of tail score.
Repeat till folding square and consistent.

The idea behind this method is to reduce the rollers from interacting with the sheet that maybe bowed causing the scoring problems