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Perfect binding that's slower… but faster

Mar 1, 2001 12:00 AM

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Speed is king — but where it once was found in cycle times, it's now centered in the makeready


A few years ago, if anybody had predicted that a perfect binder that cycles at only 5,000 books per hour would be one of the best investments a printer could make, that person would have been asked to have his or her head examined. Speed was king, after all. Perfect binders were cycling at 20,000 pieces an hour, and industry rumors took the number even higher.

Yet as many as 15 years ago, there were individuals who cautioned against higher speeds in book manufacturing. Gerald Mielke, formerly of Fuller Adhesives and now an adhesive binding consultant, is perhaps one of the most knowledgeable perfect-binding experts in the world. In a presentation to the R&E Council Bindery seminar, he once stated: “If anyone wants to achieve quality bindings, the slower, the better!”

Needless to say, this declaration fell on deaf ears. Everybody wanted speed, desirable for magazine production and large runs of softcover bindings.

Times have changed. During Drupa 2000 and Graph Expo ’00, Müller Martini (Zofingen, Switzerland) introduced the Acoro perfect binder, which does what Mielke predicted: It delivers a high-quality, adhesive-bound product at slower speeds.

Better yet, it combines speed with quality — not running speed, but reportedly the fastest changeover time of any binder on the market. Experts now agree that for most jobs, reducing makeready time is more important than the machine speed during production. At Drupa, this writer was present when a new record was broken: The entire binder-gatherer, trimmer line was changed in only 54 seconds. The changeover was from an approximately 5.5 × 8.5-inch, one-inch-thick book to an 8.5 × 11.5-inch, half-inch-thick book block (DIN A5 to DIN A4, to be exact).

Granted, these were Müller Martini technicians who knew how to recall preset computer programs, which then activated built-in motors. The servo motors then made the actual adjustments automatically. Nevertheless, a five-minute-or-less changeover is possible in an actual industrial environment.


These days, actual runs are getting much shorter, and many want to produce printed and bound products “just-in-time,” eliminating costly inventories. On-demand publishing requires runs of just a few hundred copies or less, yet these bindings must match the quality of larger runs.

For these reasons, industry experts concentrate on fast changeover capabilities, superior quality, and for many book manufacturers and trade binders, versatility. Users need to be able to adjust quickly to various binding methods, such as switching from hotmelt to PUR or to cold emulsion, for their increasingly complex products. The industry is coming across many different job demands, from softcover to lay-flat bindings and on to various book structures, such as capping book blocks with linings and using combined end sheets.

No other work in our industry causes so many challenges as does “perfect” binding. This bindery expert has seen many unfortunate incidents that caused serious perfect-binding flaws — 95 percent of the time, they were due to operator error. Such problems often originate in multiple-shift environments, where every operator seems to have a particular idea of how to cope with a binding task.

Most operators, unfortunately, lack the necessary skills or training to make such decisions. When we analyze the perfect-binding quality problem samples sent to our laboratory, poor judgement made during troubleshooting tasks always ranks as the No. 1 reason.

Vendors have concentrated on eliminating human factors from the finishing process. The electronic reading of signatures, for example, has eliminated ongoing complaints of missing parts, upside-down signatures and more.

The problem of human mistakes has recently become worse due to the severe shortage of skilled labor. As one German industry expert recently observed, “The binding industry is unable to attract young people out of school with the best scores, yet the machinery and tools used in this trade get more complicated every day.”


Fortunately, new software makes life easier for operators, and that is where the Acoro is setting a good example for future developments.

Touchscreen technology and full-color visual graphics guide an operator through every step. A skilled bindery person can preset all production data right on the binder or via a link to a PC in the production-planning department. The actual machinery operator only needs to retrieve the data programmed for a specific job. He or she can see data relevant to the thickness of the book block, for example, on the screen.

Instructions on the screen then guide the operator through setup procedures — but servo motors take care of the 35 setup steps and adjust the binder to the preselected values. The settings activate and set up the following stations automatically:

  • Infeed raceway clearance
  • Clamp opening
  • Front guide on leveling shelf
  • Pressing disk and covers on spine preparation system
  • Positioning of side glue wheels
  • Glue film length on spine and side gluing stations
  • Hopper guides on drum cover feeder
  • Accuracy of cover infeed and cover alignment
  • Scoring tools
  • Book thickness setting at cover nipping station
  • Raceway clearance at delivery with laydown device.

The gathering machine and inline three-knife trimmer can also be set up in a similar fashion. The gathering machine and perfect binder are synchronized electronically, using shaftless technology. This allows gentle acceleration from zero to 5,000 copies per hour. The results are gentle startup and braking modes, without sheets slipping inside the binder. The Acoro can produce book blocks with thicknesses from 0.125 inch to 2.375 inches (3 mm to 60 mm).

New spine preparation technology is optimized through a combination head comprising a milling head with notching blades, a ring brush and/or a sanding disc. Spacing of notches, so important for a quality product, is directed by a frequency-controlled drive. If sewn books are glued off, the entire spine preparation station is lowered pneumatically. Standard equipment includes a second spine preparation station that allows for the installation of a fiber rougher. This is an important tool for processing coated paper stocks, which often contain more fillers than fibers and can cause binding problems. The binder's fiber rougher copes with such difficult-to-bind paper.


Specially coated twin-roller gluing stations are used on the Acoro. For hotmelt, the glue pot has two applicator rollers and a separately heated backspinner. Electronic monitoring of the glue temperature helps ensure consistent binding quality. (This is very important — this is where most binding problems originate!) A freestanding premelter with a supply hose automatically maintains a uniform glue level. A special glue station is used for PUR. It can be preheated offline and rolled into position when needed, thus allowing quick changeovers from one adhesive to another, depending on job requirements.

The PVA cold emulsion station is similar to those previously described and can be used for high-quality book blocks with lay-flat bindings, such as Otabind and RepKover, or gluing off sewn book blocks.

Side-gluing is done with hot melt using cam-controlled doctor blades that are adjustable on-the-fly, for precise glue applications. The width of the discs is interchangeable.

On all of these gluing systems, the glue film length is automatically set by the commander. On-the-fly fine adjustments are possible, however. An optional crash feeder station is a welcome addition for any book manufacturer that must process sewn or adhesive- bound hardcover book blocks. This feature also allows for production in various other binding styles, including Swiss brochure and Otabind.


Müller Martini had three Acoro installations in Europe around the time of Drupa. This writer had a chance to see two in Switzerland. The Burkhardt Bindery (BuBu) near Zurich is one of the most innovative in the world. In the 1970s, I observed video technology being used there to monitor individual signatures on the gathering machine. This first attempt by a local university was not successful, but it did prove that Burkhardt has always been a true leader with regard to new technologies, seeking new solutions to cope with everyday binding problems.

When the time came to replace an older perfect binder, owner, president and director Hans Burkhardt did his homework, comparing all existing perfect-binding models on the market. He selected the Acoro perfect binder and says he does not regret his choice.

BuBu is known for high-quality jobs, soft covers, annual reports (PUR) and most of all, hardcover bindings, including coffee table books. According to Burkhardt, the Acoro investment commences a new era in the company's business activities. “We are now a good choice for high-quality, softcover jobs and annual reports as well,” he says. He says work on the Acoro results in higher productivity, thanks to the shorter setup times.

Schlatter Bindery is a slightly different business. This company offers a range of services, similar to a typical trade bindery in North America, including folding, saddlestitching and mail-order services. Book production, however, remains a vital part of its bread-and-butter business, according to managing director Adrian Krenger.

Schlatter is located in Bern in extremely tight quarters. Its goal, as with most trade binders, is to react quickly to customer requirements. Fast changeover capabilities are therefore essential. With the Acoro binder, the company can meet tighter deadlines, and adjust to smaller editions as well as split runs.

According to Krenger, the new binder has resulted in higher output, smoother operation, fewer errors, less waste and improved productivity. His operators reportedly appreciate the equipment's user-friendliness and reliability. He says the people most pleased are Schlatter's customers, as the bindery is able to deliver jobs when others cannot, even if it is only a partial advance delivery. When the remaining perfect-bound products need to go down the binding line, he notes that one touch of the screen recalls all former settings.

The Acoro Binder can be an ideal solution for binding small to midsize runs. An Acoro installation is now up and running in Milwaukee, with other installations to follow. Perfect binding, perhaps, finally gets closer to being perfect.