“Outside the Box Thinking When Folding“
At Kessler Druck+ Medien (print + media), based in Bobingen /
Germany, folding used to be a neglected part in the production
process for a long time. However, Kessler took the opportunity of
upcoming investments to look at their workflow from a new
perspective: they started in the finishing section and ended up in
the prepress department. Now, Kessler is using a new Stahlfolder TD
112 with a pneumatic twin-lay system and developed individually
tailored imposition schemes in their prepress department.
"Put the rule to the test ", says Arnfried Sittner, managing
director of Kessler Druck+Medien in Bobingen, a town near Augsburg
in Southern Germany. He believes that you have to literally grasp
something in order to fully understand it. And Mr. Sittner makes
you fold: an A5 sheet four-times conventional crossfold - another
sheet: first zickzack parallel to the oblong sheet side and then
another zickzack reducing the long sheet side and finally another
fold by half.
The result: not only is the second version a more gentle and
precise way of folding, it also delivers 4 additional pages on the
sheet - instead of 32 pages there are now suddenly 36 pages on the
sheet. In daily 3b-format-production, this means fewer sheets and
fewer signatures for the same job volume. And on top of that the
sheets get folded in the same paper grain direction as they were
The prerequisites are new imposition schemes together with
the possibility of oblong feeding into the folding machine - which
ends-up in an overall higher productivity. Or in other words:
completely rethinking of traditional folding processes!
New approach. For a long time, folding at Kessler has been
treated as an orphan - like with many other traditional sheetfed
offset printers as well, says Mr. Sittner. The technology was
antiqued, processes not as efficient as they could have been. "We
went down to the fundamental principles", explains Mr. Arnfried
Sittner. "fundamental" means for Kessler on one hand, to have a
close look at throughput times, performance, portfolio and volume.
On the other hand it meant not only to look at folding or finishing
as isolated steps but to create a holistic approach for the entire
company: "We do not only process data, print or finish - we are
producing integrated printed products", says Mr. Sittner.
"Therefore we also think in terms of a final printed product, not
of individual production steps anymore".
The focus for Mr. Arnfried Sittner is the processed material
- namely paper. His credo: "Paper is a living raw material and the
less it is being stressed and manually handled, the smoother it's
going to be processed." Starting from the paper mill delivery and
continuing all the way through the entire production chain. As a
consequence, Kessler for example uses long perfecting presses, all
of them equipped with Preset-Plus feeders and deliveries from
Heidelberg, to cut down manual interferences to a minimum.
Therefore the smooth handling of the paper also was an important
aspect when it came to a new investment into a folding machine. "If
your press already provides you with perfectly palletized sheets,
you definitely want a folder which feeds the sheets without
touching them again. Otherwise all your efforts for accurate paper
handling prior to folding were wasted", Mr. Stittner is sure.
"Gentle paper handling means faster production speeds, better
quality, less sources of errors and faster response times."
Stahlfolder TD 112 with pneumatic twin-lay system. In his
attempt to create a holistic solution, Mr. Sittner counted on the
development support of Heidelberger Druckmaschinen AG - in prepress
and press as well as in the finishing section. "Heidelberg
appreciated the attempt to handle paper in a different way", says
Mr. Sittner. "This was a very impressive experience for us."
And finally, the ideas materialized in technical solutions:
with the new pneumatic twin-lay system now available for the
Stahlfolder TH- and TD-folder series - launched by Heidelberg on
Ipex 2010 and in daily production at Kessler Druck+Medien with a
Stahlfolder TD 112. This technology facilitates oblong
sheet-feeding and at the same time increasing the productivity by
approximately 30 percent. By feeding sheets oblong and folding in
the first parallel folding unit, the reduced infeed length of the
sheet directly translates into higher productivity at the same
physical machine speed. However, on the second folding station,
which is arranged at a 90 degree angle, again the full infeed sheet
length needs to be transported. In the past, this resulted in a
much higher speed of the second folding station, creating folding
problems and a deterioration of quality.
With the pneumatic twin-lay system the folded sheets are
being aligned and transported prior to the second folding station
on two parallel side lays. This way twice as many sheets can be
transported and thus the speed of the second station can again be
reduced to the half. Quality is being increased, the material is
handled more gently and the folding process becomes more stable. In
addition, as mentioned in the above folding example, oblong feeding
in combination with the new imposition schemes also makes the most
of the printed sheet and can place additional pages on the sheet.
At Kessler this meant creating new imposition schemes, testing and
designing an imposition scheme catalog for technical and sales
staff to promote and counsel their customers. "We have re-designed
a good share of our own product portfolio, other parts have been
modified or extended.", says Mr. Sittner. The key to success was to
look at the final products from the end of the production process
and to include all participated people in the process. A special
focus lies in the cooperation between prepress, which is taking
care of the imposition schemes, and the finishing section. "We have
the advantage of being a full service provider", says Mr. Sittner.
Certainly, both Arnfried Sittner and Volker Walz of
Heidelberg Postpress agree, the Stahlfolder TD 112 with pneumatic
twin-lay system is not suitable for every print shop and each job
structure. "The machine is designed for long runs. If fast
make-ready is crucial, then our Stahlfolder KH 82 is used.", says
Mr. Sittner. "The TD 112 is a machine designed for an industrial
print production process and needs to fit in the individual company
Martina Reinhardt (Deutscher Drucker Nr. 12, 2011 / Germany)