Trouble Tri-Folding

[CSimpson]

I am doing a letter fold but do to the poor layout I am having to make a big adjustment on the fold. The first fold is at 3 3/8" and the second is 3 13/16", and I am folding up & up & out. The edge of the inner panel edge is about 7/16" from the crease.

What is happening is the inner pannel is getting folded and sometimes torn randomly. The only thing I can figure is when it makes the second fold the inside panel's edge isn't going into the rollers flat and that is likely due to the distance it is from the next fold. Is this something I just have to live with or is there a way to set this job up so that I wont have to fight this problem?

 

[RGPW17100]

Try folding down or up and down. When the inside flap is too far from the fold it tends to dog ear. I have seen this happen as well but have usually been able to get around it with using different gates, roller adjustments or adjusting the infeed guide to square.

 

[Al Ferrari]

See these two links:

Folding Machine Tip to Eliminate Bent Corners on Folded Brochures

http://www.dblequip.com/PDF/Basic Paper Folding Machine Concepts.pdf

1. The discussion at the first link suggests a tip to massage the lead edge of the stock manually to combat the problem even on machines with only a parallel unit.

2. The diagram on page 1 of the second link shows an up and down set up. Draw an analogous similar one of YOUR OWN for an up and up setup with a closed 2nd deflector. Then note that after the first fold, the original lead edge is forced against the closed deflector (in your diagram) and bent around roller 2 in such a way as to exacerbate the curl of that edge so as to increase the conflict when the second buckle is formed and pinched at rollers 3 and 4. By comparison, in the up and up setup, the the original trailing edge is the one that will potentially conflict at the making of the second buckle, as it is similarly bent around the "main drive" roller, BUT not against a closed deflector. This why an up and down setup sometimes solves this problem.

I will also mention in passing that adjusting the position of the first fold pan can play a role in the problem in the up and up setup. But by far, the simplest remedy is to stay with the up and up setup and massage the lead edge of the stock as hinted at in the first link.

Al

 

[ondemandbindery]

I am doing a letter fold but do to the poor layout I am having to make a big adjustment on the fold. The first fold is at 3 3/8" and the second is 3 13/16", and I am folding up & up & out. The edge of the inner panel edge is about 7/16" from the crease.

What is happening is the inner pannel is getting folded and sometimes torn randomly. The only thing I can figure is when it makes the second fold the inside panel's edge isn't going into the rollers flat and that is likely due to the distance it is from the next fold. Is this something I just have to live with or is there a way to set this job up so that I wont have to fight this problem?

What type of folder and model? What is the quantity? What is the stock and how fast are you running? Lots of options and yes that is a pretty healthy gap ya got there..........