by: Kevin Rickard
In our industry, the mention of specialty folding often leads to discussions about intricate folding projects, such as the iron cross or some roll, gate, or accordion folds. But sometimes specialty folding simply refers to the ability to work with thick, thin, or unusual paper stocks.
For specialty folding projects to be successful, bindery experts need to participate during the project design stage so they can help choose the right processes and equipment for each job. The best of these specialty folding experts can handle large volume projects and offer creative solutions to formidable challenges.
Specialty folding is, well, special, because an expert knowledge base is required to produce complicated folds, sometimes with glue, in high volumes with little or no error. Specialty folding experts know what equipment is suitable for which jobs. For example, buckle folders are less efficient with stock 12pts or thicker, and plow and knife folders should be used for such jobs. Knowing which resources to use prevents a lot of potential snags from becoming full-blown production problems. Some types of unusual miniature (at least one panel shorter than two inches) and oversized (large format) work qualify as specialty folding, too. Then there are the inline applications of EZ-release, permanent, or removable glue.
Machines and Paper Stress
Understanding specialty folding requires a grasp of science, or physics, to be exact. As sheets travel through the fold rollers and into fold plates, buckle folding machines apply different amounts of stress to the front and back ends of the sheets. Every fold has two sides: one heading into the plate, and the other being pushed from the back by fold rollers. The side of the fold that’s being pushed forms a “buckle” when the front end of the sheet hits the stop at the backend of the plate. As the sheet buckles, tremendous stress occurs in the paper on one side of the fold, but not the other. The side being pushed by the fold rollers gets a severe bend. If the stock is over 10 pts, fracturing of the paper surface or fibers can occur.
Folding speed stresses paper at a geometric rate of progression. For example, if the stress on a sheet is “5” when the speed is “5” (these numbers are only meant to be relative), doubling the speed to “10” means the stress jumps from “5” to “25” (instead of the linear “10”). In this case, doubling production speed translates to a five-fold increase in stress, perhaps enough to ruin a project. Therefore, many jobs that appear to be improperly setup are simply being run too fast.
Without proper planning, paper stress created during right angle folding can become a problem. The structure of paper is such that it is stronger under tension than under compression. When poorly designed folding sequences cause two panels to “fight,” the top one under tension always wins and the bottom one under compression always wrinkles. If a panel is trapped during right angle folding, wrinkling results.
In general, cracking usually occurs on the first fold. Why? As the buckle starts in the right angle section, the first fold bends around a very tight corner, greatly stressing the first fold. Unless preventative measures are undertaken, the result is poor quality.
Compliance demands led the pharmaceutical industry to find a way to include dosage instructions, risks, and even usage diagrams in all packaging – boxes, bottles, and other containers. That shift to miniature folding has caught fire in other consumer industries, such as personal electronics and cosmetics.
Now, companies seek to place even more information on larger sheets of paper. Folding those sheets down small enough to fit in the product package truly is specialty folding. When possible, get creative by using gate folds, onion skin stock, or maybe a miniature iron cross fold. The small size isn’t a limitation, but rather an opportunity for specialty folders to show off their creativity.
The applications for miniature folds in product placements continue to grow. For instance, companies that ship products to multiple countries must provide the same folded instructions to all markets, but in different languages. A specialty folder gives clients the option of including instructions in 10 or more languages on one sheet of paper, resulting in significant packaging and inventory savings.
Running gatefolds multiple-up is fraught with danger. To avoid gatefold “pullout” (an unintended fold located approximately 1/8″ away from the intended fold), fold rollers should be loosely set. Although one-up work isn’t affected by running gatefold projects with loose fold rollers, multiple-up work certainly is. Since operators can’t get solid grips on gatefolds as they travel though the slitter shaft, slits are usually crooked, ragged, or both. Since two-up formats don’t yield much more product than one-up production, designing multiple-up gatefolds projects rarely makes sense.
Gatefolds may have short gaps (less than ¼” total gap), no gaps, and wide gaps (more than 2″ gap). Since most commercial gate folding plates don’t handle these types of projects well, make sure your bindery has the necessary specialty machinery for your job.
There are few universal rules about what’s possible in the world of tricky folds. Some projects are possible and some are not. This is true most commonly with folds with lots of panels, folds at unusual angles, diagonal folds, and unusual die cut shapes.
Naturally, some printing sales representatives try to avoid bidding on work involving tricky folds. But with a strong specialty folding partner, these types of projects become fertile sales areas. Printing sales representatives who figure out how to produce unusual projects are more valuable to clients than the ones who prematurely pass on tough requests. Here is a short list of some folds that are realistic and image enhancing:
- Iron cross folding
- Pop-up folding
- Multi-directional die cut folding
- Paper-doll style folding
- “Staggered accordion” folding
- “Swinger” folding
- Narrow gap, no gap, and wide gap gate folding
- No apparent side guide folding (ovals, circles, etc.)
- Miniature folding with panels as short as 7/16
- “Layflat” miniature folding (with or without using glue)
- Folding sheets as large as 80″ long
Expert specialty folding companies provide trouble shooting and design advice services to printers and their clients. Some of these companies have even invested in staff machinists and engineers that design and customize bindery equipment. When faced with a tough folding project, turn to a trade partner with expertise in folding. Specialty folding can be a profitable revenue stream with the right specialty folding company as a resource.
Kevin Rickard is vice president of Rickard Bindery and current president of the Binding Industries Association International. He can be reached at (800) 747-1389 or email@example.com. Rickard Bindery serves printers coast to coast and specializes in discovering solutions to challenging bindery jobs.