Paper Technology Journal - Voith

Fig. 6: Existing supercalender for SC paper before
the rebuild to the Janus Technology.
Fig. 7: Calender after rebuild to the
Janus Technology.
capable of processing the production
quantity.
In order to provide a degree of reserves
on the part of the calender, also with a
view to an increase of the PM speed to
1400 m/min., this customer considered
to fit the three calenders with a zero
speed flying splice system at the unwind.
The result of discussions during the project
phase was that one of these calenders
could be taken out of operation once
the two remaining ones would have been
rebuild to the Janus Concept.
Fig. 5 shows that the two remaining
calenders, after the rebuild to the Janus
Technology, without the originally
planned Flying splice retrofit, have a
speed reserve of 100 m/min, even if the
unrealistically high availability of the PM
is based on 100%.
In order to achieve this great potential
and apart from all changes carried out
during the above described example, the
heating rolls are also changed. Apart
from the higher calendering temperature
of 140°C, these new rolls are also provided
with smoothness and gloss promoting
SUME ✷ CAL surface plating.
As, with a calendering speed of almost
1000 m/min, also high technical demands
are placed on the reel, Sensomat Plus-Eunits
in the winding up system are used
with this project.
Fig. 6 shows the original situation and
Fig. 7 the final condition of the calenders.
Although the drives of the supercalenders
supplied in 1987 were not designed for
the data normally applicable with the
Janus Technology performance or speed,
they need not be exchanged, as the power
requirement of the JanuTec plastic
rolls in comparison with the old filled is
so much lower and as the speed ratio
could be adapted by modifying the diameter
of the new drive roll.
With both projects, the Janus Technology
and clever selection of the elements from
the Janus modular design system
enabled not only the set target to be
reached, it is also possible to plan for
future expansion and, and this is of special
importance, any of the newly
installed elements can be used again.
In the case of our Finnish customer, the
potential for a further substantial qualitative
and quantitative increase in performance
lies in the heating rolls and their
SUME ✷ CAL plating additionally promoting
gloss and smoothness.
As far as our German customer is concerned,
the automation of the winding
(flying splice) process originally requested,
in addition to the already existing
speed reserve, creates a potential for
every possible increase in the paper
machine speed.
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