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Chief Folding Fanatic

Trish Talks Finishing

By Trish Witkowski

About Trish

Trish Witkowski is Chief Folding Fanatic at the online community foldfactory.com. She holds a bachelor of fine arts degree in graphic design and a master of science degree in Graphic Arts Publishing from Rochester Institute of Technology's School of Printing Management and Sciences (now the School of Print Media).

An award-winning designer, Trish held the position of creative director for a Baltimore-based agency for six years, and has taught design and desktop publishing at the college level. She has a specialized expertise in the area of folding and is the creator of the FOLDRite™ system, a 2004 GATF InterTech™ Technology Award winner.
 
Trish frequently publishes articles for graphic arts industry publications, and has written three books on the topic of folding: A Field Guide to Folding, Folding for the Graphic Arts: A Teacher's Handbook, and FOLD: The Professional's Guide to Folding.

 

Heidelberg Doubles Production Speed with ‘Frog Fold’ Technique

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I’ve been dying to write about this. When I was at the PRINT show, I got a call from Dan Maurer, Heidelberg’s VP of Postpress Product Management, asking me to come take a look at the new “frog folding” technique they were demonstrating on the show floor. He said they were nearly doubling the production speed for signature folding. I wanted more details, but he said I had to come and see for myself.

Of course I broke land-speed records to get to the booth (not an easy thing to do in heels, by the way). When I got there I was shocked at what I saw. Heidelberg developed a way to increase productivity for signature work by rotating the sheet to feed oblong with a special twin lay attachment and pneumatic gate in the first folding unit. They call it “frog folding” because the sheets “leap frog” one another into two parallel side lays. Confused yet? It’s a little hard to explain.

Steven Calov, Heidelberg’s Postpress Product Manager sent me an explanation of the process:

“Our ‘frog fold’ solution achieves both top folding quality and dramatically improved productivity by combining lower-speed production with a high number of cycles, based on a simple turn of sheets in the feeder. Here’s how it works:

Sheets are fed oblong at the feeder. Depending on the sheet format, this can lead to an increased performance of approximately 30 percent at the same machine speed, due to the shorter infeed length of the sheet (see Illustration 1). 

Illustration 1: Rotating sheet to oblong fold, gain 30% productivity at the same mechanical speed.
Heidelberg Frog Folding Illustration 1

Until now, the limitation of oblong feeding has been transferral of the speed problem to the second folding station, because there was no reduction of the infeed length and the full sheet length still had to be transported (see Illustration 2).

Illustration 2: What could be done previously.
Heidelberg Frog Folding Illustration 2

To resolve this problem, Heidelberg developed a pneumatic twin-lay device that enables the alignment and transport of folded sheets in the second folding station at two parallel side lays, reducing the speed of the second station by 50 percent. In so doing, the sheets travel over or “leap frog” one another in order to align with the register of the twin lay. While the first station runs at full speed, the second station functions in a different way to increase productivity (see Illustration 3).

Illustration 3: Heidelberg’s Twin Lay.

Heidelberg Frog Folding Illustration 3

There are additional advantages. The first fold enables the user to line up all the pages head to head, eliminating the lateral movement that could occur in traditional folding, and yielding two parallel folds in the eight-page section. The benefit here lies in better control of crossovers. Overall, the net result of simple modifications like these is to increase productivity by means of the oblong feeding of the sheet, and to improve the quality of the fold by virtue of the slower speed in the second station, making the folding process even more stable.”

Pretty cool. To give you a few stats to consider, on average, you could expect to run production numbers of about 8-11,000 sph on a modern folding machine. With this new configuration, you could be running 17-22,000 sph, depending upon the quality of the stock. They were running at 22,000 sph at the show.

This special configuration will require the modification of folding schemes and potentially a larger buckle plate folder, but all in exchange for higher output, increased quality and savings over the entire production chain. Sounds like a good deal to me.

Heidelberg’s high-performance Stahlfolder TD and TH series folders will offer the pneumatic twin lay device as an attachment on all new purchases from Q1 2010.

For more information about this innovative new device, please contact your local Heidelberg Postpress Specialist, or contact Stephen Calov directly at Steven.Calov@heldelberg.com

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COMMENTS

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Most Recent Comments:
Streven Calov - Posted on December 05, 2009
Yes the frog fold uses a modified twin lay and a new pneumatic divert gate at the exit of the 1st that allow us to produce upwards of 22k an hour doubling the normal output of signature work on a Stahlfolder. Yes the inital investment in a larger sized folder is required to turn the sheet however the press department today is manufacturing sheets between 12 to 18k an hour and we require the horse power in bindery to keep up with the pace in the press room. You only need a two station machine vs a typical 3 station folder.
Joe Rigby - Posted on December 04, 2009
No one has invented something new. We have had the ability to do this for a long time. The main problem is you need a folder at least 38" wide. We have one, an MBO 40x56". How much do these folders cost ? I'll bet close to $200,000 It's tough to spend that much money today.
Rob Kuehl - Posted on December 04, 2009
Nice article.
Click here to view archived comments...
Archived Comments:
Streven Calov - Posted on December 05, 2009
Yes the frog fold uses a modified twin lay and a new pneumatic divert gate at the exit of the 1st that allow us to produce upwards of 22k an hour doubling the normal output of signature work on a Stahlfolder. Yes the inital investment in a larger sized folder is required to turn the sheet however the press department today is manufacturing sheets between 12 to 18k an hour and we require the horse power in bindery to keep up with the pace in the press room. You only need a two station machine vs a typical 3 station folder.
Joe Rigby - Posted on December 04, 2009
No one has invented something new. We have had the ability to do this for a long time. The main problem is you need a folder at least 38" wide. We have one, an MBO 40x56". How much do these folders cost ? I'll bet close to $200,000 It's tough to spend that much money today.
Rob Kuehl - Posted on December 04, 2009
Nice article.