By Beatrix Beckmann

The printing process is the interaction of a number of different factors. It is only possible to produce top quality if the newspaper press, materials and the printer working at the press interact successfully.

Printing blanket manufacturer Duco presented its new DucoSmart solution.
Photo courtesy of Ifra

Mutually matching these components is of vital importance especially for modern, high-quality four-color newspaper printing. A prominent role is played here by the consumables: ink, paper, plates, fountain and cleaning agents, roller coverings and printing blankets (see also the June 2002 issue of newspaper techniques with special focus on materials).

Accordingly, numerous manufacturers active in these areas were represented at last year’s IfraExpo. Product developers must react to dynamic change in newspaper production and help shape these processes with corresponding solutions.

The types of products include not only materials that guarantee consistent quality but also products and solutions that improve on what is already proven by introducing suitable modifications, or adapting to market conditions by selecting new raw materials.

Printing inks

Ink manufacturers today are increasingly offering ink series for high-speed presses with a view to satisfying the growing demand for color newspaper printing. But the wide range of press configurations calls for a different matching of the inks in each case.

Felix Böttcher of Germany presented its various material solutions, including a new inking roller compound and new printing blankets.
Photos courtesy of Ifra

Among its many news ink solutions, Sicpa-Sinclair of the Netherlands featured its recently developed Newstech inks, which the company claims give the printer the possibility to reduce the amount of water on the press.
Photos courtesy of Ifra

There are different inks for high-speed presses equipped with conventional inking systems (with overshot or undershot ink duct blade) and for presses with keyless inking systems.

A further distinction is made between mineral oil-based and vegetable oil-based inks and their combination, respectively. In addition, inks containing a higher pigment concentration for lower ink consumption are offered. The program is extensive in order to satisfy all requirements (e.g. Coldset Matrix from Sun Chemical).

The globalization of the market continues here as well, as evidenced by the recent merger between Druckfarben Gebruder Schmidt and Flint Ink Europe.

Besides newspapers and advertising freesheets, magazine-type products, inserts and other semi-commercial products are being produced on standard and improved newsprint. More exacting demands are being made on ink quality.

The coldset offset process provides the potential for high-quality and economically attractive print products in the insert and magazine segment.

Newsprint

For semi-commercial production, paper manufacturers offer a wide range of classical newsprint for the coldset-offset process: improved newsprint as well as tinted newsprint or coated papers for running on standard newspaper presses.

Newsprint grades are now offered for digital printing like UPM DIGI Brite from UPM-Kymmene or Newsprint for digital printing, from Stora Enso.

Waterless offset

The fact that new press concepts often require the development of new materials is best illustrated by the example of the KBA Cortina for waterless newspaper offset printing.

Printing by the waterless offset process — in a narrow production window — requires aimed matching of the materials. To this extent, the close cooperation between the plate, paper and ink producers and press manufacturer has paid off. This cooperation was considered to have produced highly positive results already at the development stage. In the meantime, the waterless newspaper offset process has progressed beyond the test phase.

The first double-width KBA Cortina was installed at Reiff Zeitungsdruck in Offenburg, Germany, where it is already being used in production.

It is necessary to gather information about the Cortina’s efficiency, advantages and limitations as well as possible new market segments for waterless coldset. Besides formulating the ink — including the tack value — it is important, by selecting the appropriate raw materials, to guarantee temperature stability. This is supported on the press by a quick-reacting control. It is also important to gather experience for a practice-oriented operation. Data should be collected about long production runs, length of plate life and the behavior of press and materials in continuous operation.

The demands of printing faster

The trend towards increasing the printing speed of the latest press generation places growing demands on the technical characteristics of the ink and fountain additives (ink/water balance, misting and smearing behavior). Thus, there are inks that allow a reduced use of fountain agent in the press, with the objective to guarantee faster absorption, minimum set-off and a high degree of color brilliance.

High press speeds raise the temperature in the press. The causes of the heat development are the internal friction in the elastic-viscous roller coverings of the inking system, bearing friction and the conversion of mechanical-to-heat energy by the splitting of the tacky ink.

Tiny ink particles are thrown out of the roller gap (misting), resulting in a soiling of the press.

The manufacturers counteract this by changing the recipes for both the inks and the inking roller materials. This approach can reduce temperatures and better adjust ink misting.

Printing blankets and roller materials

The consistency of the printing blanket, especially over a longer period, is important for high-speed presses. The useful life of the printing blankets in the press can be increased by changed surfaces and suitable characteristics (ink and water acceptance), reduced swelling during the print run and improved stability on the cylinder.

Duco showed its new DucoSmart system for mounting blankets and bridging the lock-up gap on conventional web printing presses.

New damping roller materials, especially designed to suit the recipes of news inks, also show a clearly improved dimensional stability.

Cooperation with customers takes top priority

Intensive cooperation with the customer is being considered increasingly important. The customer should be offered technical support and a long-term partnership. Suppliers offer various programs for this (e.g. Service Bridge from Stora Enso or Clinics from Coates Lorilleux).

Within the PrintCity project, the cooperation between the members of the Web-Systems Activity Group extends beyond the entire web offset product process with the objective of improving results. On the material supplier side, this work is supported by, among other things, technical audit programs (e.g. from Sun Chemical) and standardized measuring systems in the paper sector (UPM-Kymmene).

With Printcom, MAN Roland offers a concept for a new service offer in the printing materials area. Consumables can be tested and optimally matched up at the MAN Roland Graphic Center for product presentation and training. This know-how is then passed on to the customer with the “Get started” print start-up package with basic consumables.

In the interest of the customer and research in relation to high-speed processes (web travel, reel change) and resulting problems, Stora Enso and UPM-Kymmene offer a service with high-speed cameras.

In Barcelona, UPM-Kymmene also presented developments together with Auramo Oy. The Spider is used to measure reel out-of-roundness and Grip Force Tester optimizes the force with which paper reels are gripped.