The Debate Presses On: Offset vs Digital

As the new millennium continues to dawn, digital printing is no longer a “technocuriosity,” but the heir apparent to offset lithography. Benefits including speed, quality, and cost are just some of the selling points that trickle off the tongues of press manufacturers across the nation, but is traditional offset equipment really about to go the way of the letterpress? After all, AM radio is still around, even if nobody under the age of 40 listens to it.
Obviously, choosing to go digital or not is left to individual printers to decide, dependent upon their specific needs, not the mainstream’s. Still, it’s difficult to argue with success, and many printers may soon decide to “follow the leaders.” Here’s a look at some current offerings:
A.B. Dick Co.
A.B. Dick Co. has launched the PrintPro 34, a two-color, twin-tower portrait press with landscape-format attributes.
It comes in two models – one with a universal and turbo stream feeder – plus another with pneumatic operation. The models also have the ability to run with polyester plates, which minimize paper waste.
According to the manufacturer, the PrintPro 34 uses the same quality of print registration found in larger printing units. Standard features include a turbo stream feeder, a convertible dampener system, and a superior inker. It also offers heavy-duty components such as helical gears that ride on tapered roller bearings, chrome-plated cylinders, and a running register. Auto crawl and auto setup ensure faster preparation for print jobs.
The turbo stream feeder has been designed to improve long production runs, using a vacuum conveyor to guarantee positive sheet delivery. The continuous load and unload component in the PrintPro 34 is another built-in feature. The convertible dampener system incorporates two major technologies. The PrintPro 34 offers integrated or segregated technologies, and the dampener offers paper-sense control.
The inking system makes it possible to use three-ink form rollers in the segregated mode and four-ink form rollers in the integrated mode. Streak-free results are achieved since the inker has multiple paths that provide even ink distribution on solids and screens.
The 8915/8920 offset press is designed for high quality and spot-color work for applications in the 500-5,000 print volume range. The 8915/8920 presses are entry-level, offset duplicators for one- and two-color printing jobs. The 8920 offers chain delivery and a 5,000-sheet receding stacker. The 8915 excels at handling short-run work with authority by using a 500-sheet chute delivery system.
The 8915/8920 uses a single-action control lever to regulate the printing sequence for each operating function. The 1-hp DC drive motor reportedly guarantees a smooth start-up that extends the life for the gears in the printer. A blower and vacuum feed system helps control sheet separation and provide accurate delivery. The 11.7×17″ maximum sheet size is complemented by two form rollers to ensure good ink coverage.
According to the manufacturer, operator involvement is reduced significantly. Since the master and impression cylinders automatically adapt to the blanket cylinder, they self-compensate for differences in the master or impression paper thickness. Additionally, blanket cleaning is not required when changing image position on the paper.
One of the latest developments of the company was the introduction of the A.B. Dick Color digital press, which was designed for on-request color production with in-plant, rapid response, and small – to mid-sized commercial printing operations. It is capable of printing on multiple substrates and is suitable for on-demand, short-run work such as brochures, sell sheets, and advertising. Its digital offset technology reportedly reduces production time.
Agfa
Agfa has announced the launch of a Chromapress digital color printing system, the 32Si. The 32Si is a single-sided, five-color printing system that reportedly operates at twice the run speed of the Chromapress 32Si model, which its design and front-end architecture are based on. An optional fifth color (white) for packaging, labeling, and other applications is also available.
With a rated speed of 14.7 meters per minute, the 32Si is designed to be productive for demanding production environments. It can print on a wide range of substrates, including foils, adhesive, cover stock, canvas, transparencies, and polyester, as well as paper. The 32Si is an alternative to conventional print technologies for packaging, labeling, posters, book covers, point-of-purchase materials, display materials, and more.
Agfa also has released the Chromapress Model 50i, a wide-format version of the Chromapress digital color printing system. The Chromapress 50i is a 50-cm-wide web-feed unit based on the Chromapress print system. The Chromapress 50i incorporates as standard features all of the previously announced advancements for the Chromapress product line, such as OmniGloss high-gloss output, next-generation toner and developer, and the new IntelliStream architecture. Output resolution, at 600 dpi, is the same as the Model 32, and the printer has screening options available in several versions.
Heidelberg
Heidelberg has introduced the world’s first 50″x70″ Speedmaster in an eight-color configuration, complete with two sheet-reversing devices, an in-line-coating system, and extended delivery. The Speedmaster SM 74 has “One Pass Productivity.” This form of production requires sophisticated printing press technology when printing four-color jobs to prevent perfected sheets from being scratched or smudged on their way to the delivery pile. The SM 74 also opens up new applications, such as the production of magazine wrappers or eight-page brochures with coated outside pages.
The configuration of the Heidelberg Speedmaster SM 74 eight-color press, which features double sheet reversing and a coating system has been made possible by redesigning the sheet guide in the delivery unit. The Heidelberg Venturi principle guides the sheet safely through the delivery unit on a cushion of air. The precise matching of the dryers to the sheet travel is significant for 4/4-color jobs. The extended delivery unit features two infrared hot-air dryers and one circulation dryer from Heidelberg DryStar, which are tuned to the sheet guide plates.
The maximum printing speed of the demonstrated press is 13,000 sheets/r. For SM 74 eight-color presses without the sheet reversing and coating system combination, the new sheet guide can increase maximum-printing speeds to 15,000 sheets/h, i.e., 30,000 printed sides per hour.
Additional innovations include a new, narrower sheet brake and sheet guide plates that consist of fewer segments.
Komori
Komori’s Lithrone 28 Perfector printer features an automated perfector changeover in three-and-a-half minutes. The company developed the double-diameter impression and transfer cylinder system. The same engineering for maximum sheet-handling performance has been integrated into the Lithrone 28″ and 40″ perfector series. The Lithrone 28 Perfector incorporates this cylinder arrangement to achieve a smooth paper flow, with reduced scratches and smearing to allow high registration accuracy. Besides protecting the sheets, this design is also said to be an ideal solution for maintaining front-to-back registration accuracy at high speeds.
Switching between one-side printing and perfecting operation is completely automated on the Lithrone 28 Perfector. Since the paper size data has been pre-entered in the AMR function of the console, the operator selects perfecting vs. straight printing so all adjustments for paper size are automated and then the changeover operation is completed automatically. The Lithrone 28 Perfector is also equipped with a backup system, including a manual control box that allows the sheet-reversing cylinder to be changed over manually.
Ryobi
Ryobi has announced a four-color, portrait format, A3-plus size offset press with Ryobi Semi-Automatic Plate Changer, the Ryobi 3304HA. The Semi-Automatic Plate Changer allows plates to be changed by button operation. This device can be used for both polyester-based plates outputted by the Plate Setter as well as metal plates. Plus, the new diagonal adjustment device is mounted on the plate clamp so that the on-press registration adjustment has been simplified, and short make-ready time is ensured for small-lot multicolor printing.
The designed of the 3304HA offset press was based on the 3304H, which Ryobi describes as the world’s first A3-size portrait format four-color offset press that has become known for its compact design and cost-effective features. The basic specifications and features of the 3304HA are the same as that of the 3304H. The four printing units consist of two sets of the satellite V-shaped, five-cylinder system to minimize gripper changes and increase image positioning accuracy. In addition, the continuous dampening system “Ryobi SuperDampener” comes standard to optimize dampening supply. The 3304HA handles a maximum paper size of 13.39×17.72″ and can print up to 10,000 sheets per hour. The standard PCS-F printing control system, which includes an operation stand, enables remote control of ink fountain keys.
Xeikon
Plastic card manufacturers can now print short runs with the DCP/32S digital color press from Xeikon, which recently acquired a controlling interest in Nipson International. The Xeikon plastic-card solution is not only capable of printing on PVC material, but also features a multifunction system from Melzer that offers a range of finishing operations, including lamination, die-cutting, and the inclusion of magnetic stripes, signature panels, microchips, and holograms. The benefits of the digital color press include fast turnaround to meet increasing demand for just-in-time, short-run orders, enhanced customization capabilities (personalized or versioned cards), and flexible operation.
The DCP/32S incorporates Xeikon’s xerographic print engine to print roll-to-roll or roll-to-sheet in five colors – the four process colors plus an opaque white – onto standard coated PVC up to 10-mil thick at a speed of 24 feet per minute. Each roll accommodates two complete cards – front and back side – across its imaging width of 12.06″. By printing directly from the digital file, without any intermediate master, the system is reportedly faster and more flexible than conventional solutions.
The DCP/32S can handle a range of cards, including products incorporating multiple layers and intelligent components. In addition to typical four-layer cards (two PVC layers laminated on both sides), the system can produce multilayer cards featuring an additional core placed between the two PVC layers. This core, for example, might contain an antenna such as those used in radio frequency identification (RFID) cards.
Reprinted with permission from The March 2000 issue of Quick Printing.
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