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View Full Version : Folding a long strip of paper...is there a machine to do this?



winchman
09-29-2012, 02:01 AM
I've been asked to design and/or build something to fold a long strip of heavy paper or fabric into a "single open gate fold". The strip starts out flat about three inches wide and several feet long, and ends up folded like this:

http://img.photobucket.com/albums/1003/winchman/2012-09-29_0054__open_gate_fold_zps06637b08.png

The folded strips will be about 1 1/2 inches wide and several feet long.

Is there a machine available that will do this? What would it be called?

kendall
09-29-2012, 04:47 AM
Could do it with a properly shaped 'guide' system. using three 'fingers' one to keep the center flat, one on each side to lift and curl the outer edges. side guide/fingers do a half flip, slowly twist so that the top surface becomes the bottom surface and folds the paper/cloth in while a roller or another finger beyond them crease it tight. End feed it for continuous operation.

BigJohnT
09-29-2012, 07:40 AM
Yea, pass it through two rolls to fold the legs 90 degrees then with guides fold the rest of the way then two more rolls to press it flat. You could run the machine with HAL...

John

Doozer
09-29-2012, 08:47 AM
Gutter brake?

--Doozer

vpt
09-29-2012, 10:11 AM
How many need to be done?

Piano hinge comes to mind.

winchman
09-29-2012, 11:05 AM
I forgot to mention that the upper side is coated with spray-on contact cement, so it can't be touched by any part of the mechanism.

The quantity is several dozen a week, but they need to be done in the minimum amount of time, of course. The current process is hand folding on a long table, and the results aren't always acceptable because the width isn't consistent and the folded edges aren't straight.

I was thinking about a raised vacuum chuck under the center part of the strip. That would hold the center of the strip flat and straight while the sides were folded over my hand, and pressed into place. Do you think that's worth a try?

Another thought was to use 3M 924 adhesive transfer tape instead of the spray-on adhesive. That would make it easier to handle the edges while folding them over.

I like the piano hinge suggestion. I'll give that some thought.

kf2qd
09-29-2012, 11:08 AM
How long and what weight paper? How many does it need to produce?

browne92
09-29-2012, 11:45 AM
Could the paper be creased first, have the adhesive sprayed, then folded? Fold it into a U shape, have a spray head that could spray all 3 insides at one time?

Forestgnome
09-29-2012, 11:55 AM
I'm thinking something like the continuous rain gutter machines. You could use two vee rollers at a 45d angle that press the paper into roller dies. That way the paper is only contacted at the crease.

CCWKen
09-29-2012, 04:01 PM
I'd make the adhesive the final step. A few rollers and properly placed folding bands and you could make hundreds of feet per minute. Use a glue roller or apply two-sided tape as it's coming out. For high production, feed stock off a roll and a cutter at the end would even give you the length. All the operator would have to do is press Start then Stop when the pile is large enough. I mean this is like the simplist process I've ever seen next to manual labor.

armedandsafe
09-30-2012, 12:18 AM
In the printing industry, we would run the paper over a table with a slit in the middle. A bar would come down and press the sheet into the slot, down to a pair of rollers, which would grab the paper and suck it through to crease it. Because you have two folds, you would then pass the sheet to another table, or reverse its orientation and return it to the first table.

This would, obviously, require that the adhesive be applied last. It is unclear just where the adhesive is located. If within the item, the the folded pages are glued to the center portion? If to the outside, then how is the finished product handled? If strip adhesive is intended to hold the folded product closed, then it is easy to apply afterwards.

Go to a local print shop and ask if you can pick the brains in their bindery. You might get some pretty good ideas.

Pops

Rich Carlstedt
09-30-2012, 12:47 AM
In the plastic film and also the paper industry, they call it 'gusseting" and these
are common machines.
They generally run nonstop (continious film path) and use bars to guide the folds
Do some research on it

Rich

Yow Ling
09-30-2012, 04:07 AM
Could use self adhesive label material put all the folds in then remove the glassine (silicone coated backing paper). The material is cheap and it removes the applying the adhesive step, material choice is good from uncoated to cast coated paper, polypropelene, Polyetheylene with dozens of different adhesives

winchman
09-30-2012, 05:43 PM
Thank you, Rich!!! That's exactly the clue I needed.

I cannot search worth a flip when I don't know what I'm looking for. :D

winchman
09-30-2012, 06:17 PM
And here it is:

http://img.photobucket.com/albums/1003/winchman/2012-09-30_1713_bag_handle_machine_zps11f6f8ca.png

http://img.photobucket.com/albums/1003/winchman/2012-09-30_1720_bag_handle_machine_2_zps2e9bbec8.png

It's a bag handle folding machine, of all things. Get rid of the spray-on adhesive, lay in a strip of double-sided fusible fleece (heat-activated fabric adhesive), and it's done.

Evan
09-30-2012, 09:35 PM
I forgot to mention that the upper side is coated with spray-on contact cement, so it can't be touched by any part of the mechanism.

Sure it can. Rollers like a pizza knife can touch the glue without a problem, especially when PTFE coated.

Paul Alciatore
10-01-2012, 06:42 PM
Sure it can. Rollers like a pizza knife can touch the glue without a problem, especially when PTFE coated.

I'm with Evan. Use a pair of pizza cutter style rollers with slightly rounded edges to pre-crease it. A cylindrical roller on the back (non adhesive) side would have two shallow grooves opposite the pizza rollers and rims to guide the strip through. Once it is pre-creased, folding it should be easy with curved side guides as shown above. The pre-creasing will maintain the precision of the fold.

Evan
10-02-2012, 01:47 AM
Another thing about paper handling is that air can be used to good effect. I have worked on many a paper handling system including folders.

kendall
10-02-2012, 06:16 AM
And here it is:

http://img.photobucket.com/albums/1003/winchman/2012-09-30_1713_bag_handle_machine_zps11f6f8ca.png

http://img.photobucket.com/albums/1003/winchman/2012-09-30_1720_bag_handle_machine_2_zps2e9bbec8.png

It's a bag handle folding machine, of all things. Get rid of the spray-on adhesive, lay in a strip of double-sided fusible fleece (heat-activated fabric adhesive), and it's done.

Ha! exactly as I envisioned when I posted my earlier reply.