Non-Stop Book Webs

Whether called Auto Transfer, Zero Make-Ready, non-stop or flying plate change, a technology is being offered by press manufacturers for switching plates without ever halting the press for plate changes. For those web printers running consistent products from signature to signature and job to job, non-stop press technology can virtually eliminate conventional press makeready times.

Where the production environment justifies it, the non-stop technology can also significantly cut paper waste, make short runs more profitable and tighten job cycles. Non-stop web presses are proving most popular among book, catalog and coupon printers (GAM Oct. 06, p.68) as well as publication printers.

Enabling technologies include servo-drives that have replaced inflexible shaft-and-gears, allowing different units and components to run at varying speeds or even stop as the rest of the press keeps printing. Modern controls and automatic plate changers are also essential to these time-saving configurations. On multi-color work, fast-reacting register, color and web guidance controls are critical to on-the-fly work.

Among the press makers offering the non-stop technology are Goss International on its Sunday presses, Timsons, Inc., on its T-48A presses and most recently, Solna Offset AB, on its Bookline press.

Goss International's Automatic Transfer (AT), available for the Sunday 2000, 3000 and 4000 commercial webs, allows operators to bring one or more idle printing units on impression while simultaneously taking another unit, or group of units, off impression.

Goss notes that Sunday press technology makes the Automatic Transfer possible. Because cylinders on the gapless Sunday presses do not require bearers, they can be mounted in pivoting cylinder housings to achieve the extra-wide, blanket-to-blanket throw-off necessary for the web to pass through idle units without contact. Separate servo drives for each printing unit as well as upper and lower blanket cylinders are critical to the functioning of the system.

Also essential to fast changeovers with the Goss AT system is the firm's Autoplate feature that allows fully automatic plate change for idled units triggered directly from the press console while the press is on the run. (GAM May 06, p.14.)

A typical Sunday press AT installation on a six-unit press, two of them AT units, would allow either 4-color printing with on-the-run black text changes applied by the AT units; or 5- and 6-color standard printing.

An arrangement comprising eight AT printing units, in use at Transcontinental, can perform 4-color form changes on the run or 5-, 6-, 7- or 8-color standard printing.

The Timsons T-48A ZMR (Zero Make-Ready) press was designed with short book runs in mind. This vertical web with its two servo-driven stacked printing units is designed for zero makeready on one-color projects. While one unit prints at speeds up to 1,500 fpm the press alerts the operator that it is nearing the end of the form. After verification that a new plate is loaded, the print unit is automatically accelerated, synchronized to the web speed and brought into register. When the form ends, the unit with the expiring form goes off impression and the new form is thrown on impression—with no loss of time and a major saving in paper waste. Timsons reports that waste in switching to the new form is 30-50 signatures or less. Plate changes with its “Easy Access” design (units slide out on rails) take two minutes on the upper unit, less on the lower unit.

The T-48A also offers important product versatility with the capability to run high quality 2-color work. Although a press stop is necessary for a plate change in 2-color mode, the T-48A press utilizes tool-less semi-automatic plate changing system and Quick Make-Ready sequence. A short web lead, with less than a 40´´ blanket-to-blanket distance, is said to provide tight register on 2-color work.

Utilizing the Timsons M7/4 open three-sides folder, the press will produce 16, 32, 48 or 64 pages from a single web.Timsons recently introduced the new T-48A ZMR2 double web, a book press like the single web version, but with higher page throughput at a higher press speed for longer run books.

From Solna Americas comes a new offering: the vertical web Bookline. (The company will be exhibiting at Graphics of the Americas March 2-4.) The first Bookline with flying plate change was delivered to Print-It, Klaipeida, Lithuania, in October, printing pocket books for the Scandinavian market.

In North America the Bookline is aimed at the high-end elementary/high school textbook market, primarily 6×9´´ books, a market ripe for new technology with an installed base of older, less productive presses.

With its shaftless drive and bearerless cylinders, the Bookline was modified to let the running vertical web pass between the stopped blanket cylinders. Waste during flying plate changes is reported as three to six signatures. Customers can choose print circumference, web width and folder to meet individual requirements. The folder can be equipped with a different cut-off cassette, allowing the possibility of different cut-offs in the same press line.

Transcontinental operates non-stop webs at two plants in Canada's Quebec province—a Goss Sunday 4000 at its Beauceville facility and Timsons ZMR presses at its Louiseville plant. The Sunday 4000 was the first to be equipped with eight AT units to provide the capability for complete 4-color, non-stop job changeovers.

“We do a lot of school textbooks, a lot of high page counts and a lot of small runs so we are in an environment where all we were doing was changing plates,” says Jacques Grégoire, senior VP of Transcontinental's Book Group. “We wanted the capability to do that on the fly.”

While Transcontinental is using the new AT press for high-quality, 4-color textbooks and catalogs in 8×10´´ and 8½×11´´ sizes, it can also run tabloid or digest-size products.

Without stopping the press for a plate change, Transcontinental can change all four colors or go from one 64-page signature to a completely different one. Running non-stop Auto Transfer on the wide-format, 64-page Sunday 4000 also means handling a tremendous amount of paper. The press can use up to 75´´-wide paper rolls and Transcontinental is outputting either a single 64-page signature or two 32-page signatures at once, with throughput at 2,800 fpm. The press runs 24/7, served by robots that keep up by rapidly separating the different signatures, palletizing them and moving them away.

“If you don't have the right environment—a high page count and if you are not using the same paper consistently—the Auto Transfer won't do anything for you,” says Grégoire. “To achieve the maximum efficiencies and economies you have to set it up for mass production and go for it.”

Transcontinental is currently printing runs as short as 10,000 on its Sunday 4000 and expects to get down as far as 5,000.

At its Louiseville plant Transcontinental uses its Timsons T-48A ZMR presses primarily for single color trade publications, limiting waste to as little as 20 signatures per plate changeover.

“The Timsons process is more simple than the Goss AT because it involves only one color,” says Grégoire. “To really be able to use the Zero Make-Ready you have to be running the same stock and trim size. It is geared for multiple signature books, publications or catalogs.

“ZMR plate changes reduce waste significantly—close to what you would have on a sheetfed—and there are also the time savings in not having to stop the press, change the plates, ramp up again and make sure fold and trim are good,” Grégoire says. “If you have the market to use it efficiently, one press can gain 25% to 30% productivity.”

www.gossinternational.com, solnaweb.com and timsonsinc.com