Web Offset is Keeping Pace

Technologies such as shaftless drives and sleeves are leading the way for web offset productivity.

WEB OFFSET PRINTING is feeling the pressure coming from the improvements being made in flexographic printing. However, similar to the other printing processes, web offset is continually making strides to reduce makeready times and improve productivity. And it's doing this while playing off its inherent strengths and capabilities for high-quality printing.

Ted Barry, vice president of sales for Matik North America (a U.S. distributor for Codimag and Giebeler), lists some of web offset's competitive strengths as: printing characteristics similar to gravure and superior to flexo where fine screens are required; the low cost of offset plates in comparison to flexo and gravure requirements; and the ease and speed of plate production in comparison to flexo plates or gravure cylinders. "An easy explanation of a good fit for web offset is a job that requires gravure-quality graphics with shorter run lengths or versions," he states.

"One of the factors in web offset's ability for quality printing is that it prints without a relief plate," says Eric Short, president of RDP Marathon. "Because it doesn't require a flexible plate under pressure, it is able to print high-quality, repeatable dots, especially on sensitive substrates. This leads to quicker makeready times and reduced waste."

Steady improvement

Building from the inherent process capabilities of web offset, press manufacturers have made great strides in the last five to six years. "There has been tremendous increases in capabilities of press and prepress, such as CIP3/CIP4 standards," says Short. "Also, vision systems have improved makeready with the ability to quickly setup the press and set color." He also adds that process control, especially in temperature regulation, has significantly improved in this time frame, with a big impact on productivity.

CIP3/CIP4 standards are designed to aid in the integration of print information from its development in prepress, through press and postpress. It comes from a vendor-based organization called the International Cooperation for the Integration of Processes in Prepress, Press and Postpress. (Note: CIP3, originated in 1995, became CIP4 when the organization added the word 'processes' to its name. For more information, visit www.cip4.org.)

Barry also points out the impact from the CIP4 standards. "Makereadies are constantly being improved, most recently through the introduction of CIP4 interfaces linking the prepress function to the press through ink-zone settings and register control presets," he says. "Many of the new generation web offset presses have makeready systems that are far different to presses that are just four or five years old."

Reduction in makeready times appears to be a major focus for web offset operations. "This is due to the recognition that further improvements in press speed will provide diminishing returns," says Barry. "Most printers, due to their job mixes, would find it difficult to truly take advantage of higher and higher speeds. Where money is made is in the pressroom, through increased on-press time from reduced makereadies and lower substrate waste."

Similar to other package printing technologies, web offset presses are also picking up on the benefits from shaftless drive technologies. Michael Aumann, vice president of sales and marketing for Brandtjen and Kluge, Inc. says that his company has strengthened its position in the short- and medium-run markets with the introduction of new shaftless technology on its offset/UV flexo web press systems. "The addition of the shaftless press technology increases the flexibility of the press, produces higher quality printing and reduces makeready times," states Aumann. "Each print tower can now be controlled independently and the operator is provided with a constant point of reference, zero point, and return point when running or setting up."

While offset printing is feeling the heat from the quality upgrades coming from the flexo-printing sector, it is also borrowing some of the technology concepts from flexo. According to Barry, one major development in offset printing is a direct result of developments in the flexo industry. This development is the use of flexo-style sleeves for plate and blanket rolls, and is addressing a disadvantage with web offset printing when it comes to changing sizes.

As an example of the impact of sleeve technology, Barry says that a cassette system (including fixed plate, blanket, and impression cylinder) might cost as much as $30,000 per print station on a 26˝-wide offset press. "An offset press developed by Giebeler Druckmaschinen of Langenfeld, Germany for flexible packaging applications offers sleeves for plates and blankets at a cost of roughly $5,000 per set, close to a similar plate roll for a similar-size flexo press."

RDP Marathon is also offering sleeve capability on its presses. "The use of sleeves is commercial and is finding its way into industry as an emerging technology," says Short. "Offset sleeve technology was promoted by several vendors at IPEX this year for variable-width printing." He believes that the use of sleeve offset technology approaches the same cost structure as UV flexo. "Capital costs are higher than UV flexo, but overall costs should be competitive when considering the life-cycle."

How about waterless offset?

Waterless offset appears to be a technology still waiting in the wings, not knowing whether it will make it to the big time. RDP Marathon offers waterless offset presses along with its conventional stable of presses, but Short sees very little movement in demand for waterless technology in the web offset area. He attributes this, in part, to the continual improvements being made on the conventional offset side of the equation.

One area mentioned by Barry that has made some progress in the last few years is in the availability of waterless inks. Several years ago there were only one or two ink suppliers, in Japan or Europe. Now, several domestic suppliers offer a wide range of inks.

Barry also sees some inherent advantages of waterless offset technology that make it an appealing option. "The strengths of waterless are its quick makeready characteristics and low waste (for example, there is no need to run the press while adjusting the ink/water balance), low-dot-gain sharpness, and applicability to non-absorptive surfaces (no water means no beading)."

One perceived problem for waterless offset mentioned by Barry, is the need for temperature control systems that increase the cost of a press. He points out, however, that presses such as Codimag's VIVA 340 that are designed for waterless printing from the beginning, avoid the problems and costs associated with retrofitting cooling to a current design.