Feeder Question

[Kaoticor]

Dear all,


Any of you have experience with 14pt board, glossy on both sides? We can't seem to run this stuff consistently, the sheets keep sticking together, giving us double sheet. We cant add enough compensation with fingers, air blasters, etc... Tried all of the normal things, fanning, feeder settings, max air, etc... With a lighter paper that is 2 side glossy, we can compensate. But this stock is just to heavy too add much correction. Any ideas? Thanks

 

[Al Ferrari]

Many here on this forum may have suggestions for you. But most readers have not visited your shop. The ones most likely to help will be the ones familiar with the same equipment, but you left that detail out.

Al

 

[Cornishpastythighs]

Do you have the parts on your feeder to run board. Fingers, suckers, brushes, heavier wheels etc. Also your air blasts/seperators may need cleaning to get maximum efficiency. I am assuming you dont often run board and your press is set up for lighter stocks.

 

[Kaoticor]

Correct you are Cornish. We mainly run .004 - .010 stock.
The paper seems to be feeding down the feeder table just fine, just the initial pickup it does not want to separate.

Al: Komori Lithrone 28
We have fingers, a heavier type of a sucker rubber, and some different wheels as well.

 

[Cornishpastythighs]

A lot of the problems can be that the feeders are not used to the heavier stock, we run mostly board stock no problems and then when we try to run thin paper its a huge learning curve.

 

[chevalier]

Is your pressroom climate controlled? I've seen things like this happen with season change causing wild fluctuations in humidity/temperature.

 

[John Arneson]

Now that we know what press you have here is a couple of thoughts.
1. When was the last time you rebuilt your feeder head?
2. Are you sure your feeder pump is large enough? I say this because around 1989 and 1990 Komori used a pump a bit too small, I am assuming simply to fit it under the catwalk.

 

[nhprinter]

Correct you are Cornish. We mainly run .004 - .010 stock.
The paper seems to be feeding down the feeder table just fine, just the initial pickup it does not want to separate.

Al: Komori Lithrone 28
We have fingers, a heavier type of a sucker rubber, and some different wheels as well.

14pt is not very heavy. We've got a L426 vintage 1986 and we can run 14pt with very few adjustments. It's possible your feeder pump isn't putting out enough blast. Check to make sure that you're able to separate at least the top 7 or 8 sheets in the pile. Make sure your fingers are high and out of the way to give the sheets room to raise.

Is the pump the type that's under the catwalk? If it is then make sure the screen and filters are clean and the blast is all the way up. Also make sure you don't have any leaks in the hoses.

We on our third pump since we got the press in 1988 so that might be your problem.

 

[Kaoticor]

Havn't ever rebuilt feeder head, we keep it pretty well maintained. The pump is from a cabinet all the way in the operator end. Nhprinter: I'll double check the screens and filters are clean, they do clog up pretty fast. Thanks,

K

 

[John Arneson]

It does not matter how well you maintain your head. They just wear out just like tires on your car. I believe the press will run best if the head is rebuilt about every 20 million imps.
It is not very difficult to do and it does not cost that much. Especially when compared to all the trip offs.
good luck

 

[Kaoticor]

It does not matter how well you maintain your head. They just wear out just like tires on your car. I believe the press will run best if the head is rebuilt about every 20 million imps.
It is not very difficult to do and it does not cost that much. Especially when compared to all the trip offs.
good luck

Thanks for the comments. Just so I understand you correctly, are you talking about the foot itself? Which parts in particular do you mean would be involved in rebuilding the head?

 

[John Arneson]

You need to replace the pick-up and forwarding suckers. The pick up suckers are a no brainer, the forwarding suckers are a bit more involved. You should rebuild the whole pick up assembly.
Look in your parts book. You need the stoppers, piston, spring, bushing, and both suckers.
Keep in mind their is a left and a right (different part numbers)

 

[Kaoticor]

Just thought I would post back here in case anyone had similar problems in the future:

-We were able to do some work on the compressor to get a bit more air blowing, that helped us get enough to fix our doublesheet issues.

-Also, after reading John Arneson's post, we looked at our feeder head a little more closely during some of our more troublesome runs. Sure enough, the forwarding suckers have slowly worn through the years and had a little bit of "play" in them. The difference between the rebuilt ones and the old ones was:
1. Old ones did not drop to grab sheet consistently. New ones dropped sharply during the fowarding sucker cycle.
2. Old ones had some "wiggle" when the sucker was extended. New one had none.

The old fowarding sucker assembly was cocking our stream from time to time. We rebuilt them and the stream straightened out right away. We have a few other sheetfed presses so I am going to make a note of this to watch in the future. It's worth the feeder trips you save in the first month alone if this is causing you issues. Hope this might be of some help if you experience the same issues

- K

 

[clivechapman]

Hello Kaoticor,
We run board all the time. I understand this is a Komori Lithrone 28 right? Had it got a Rietschle Druvac feeder pump under the footboards on the drive side adjacent the main motor? As others have said, check the blow is good to separate the sheets but also the problem may be due to the fact the board is glossy on both sides which causes the sticking together, maybe you have a static problem?

 

[clivechapman]

Did you say the feeder is picking up two sheets? If so the vacuum from the feeder pump is okay. What board separators are you using, the spring steel type supplied by Komori?