Paper Technology International 2020 - Journal - Page 67

PAPERTECHNOLOGYINTERNATIONAL
From substrate product to final reel release
Defects such as edge cracks and holes can lead to costintensive problems in downstream process steps, for example,
breaks in the winder. By connecting the winder section with the
inspection system installed on the paper machine, those defects are
reliably detected during the winding process so that malfunctions in
further processing will be prevented.
During the reel processing at the winder, the winder can
access the corresponding stored defect database of this very reel
using the ISRA Unwind Control System (UCS). The synchronization
between the stored defect information with the position on the reel
at the winder will lead to automatic speed adjustments whenever
critical defects occur. This same solution can also be used to
protect offline calenders and offline coating, or it could be used on
rewinders stopping at a dedicated defect position to patch
holes. To achieve an exact position synchronization
between the defect database of the jumboreel from the paper machine and the
current reel length on the winder,
the application of a length
code along the edge of the
paper web has proven
itself in practice. At the
winder, a code reader unit
will read this length code
and synchronize it with
the actual length of the
defect database, regardless
of how much material has
been removed from the initial
jumbo-reel.
To date, length
codes have been applied with
conventional inkjet marking
systems that cause costs due to regular
cleaning (once or twice a week), and high
consumption of ink and water. In addition, possible ink
contamination of the substrate can occur, leading to
customer complaints as a consequence. ISRA´s UCS
LaserMarker overcomes these limitations by using an
absolutely safe and reliable laser-based length code
marking system with maintenance and consumables
costs that are close to zero. In addition, distances
between the individual length marks can be drastically
reduced.
Where otherwise a mark was set every 1.000 to
2.000m, with laser-based marking units, a code distance of only 50m
is typical. This leads to a higher precision of the synchronization.
Moreover, laser-based marking systems are suitable for nearly any
paper grade, from 10 grams upwards.
Thanks to the exact position synchronization on the winder,
the Customer Roll Defect Report (CRDR) can be used to create
individual roll reports with surface defect data for each individual roll.
The CRDR places the current cutting plan over the synchronized
defect database of the original jumbo reel. With knowledge of the
exact knife positions and recording of the exact position of the web
edge, a position-accurate defect report can be created for each roll.
The role reports can then be used for further processing steps, or
provide a prove-of-quality report to the customer if necessary.
With an additional software module, the Reel Release, an
automated evaluation of each individual role can be conducted. Not
only surface defect data is taken into account, but further process
data from other sources, such as moisture, thickness, formation,
etc., can also be included.
For each individual roll, an automatic quality assessment will
be taken: whether the current quality meets the actual requirements,
the roll needs to be sorted into a different quality level, or the paper
needs to be repaired or returned to the production process through
recycling. In doing so, it will save additional costs and contribute
to the efficient use of valuable resources. Plus, it ensures that only
quality approved paper is delivered to the customers.
Automatic surface inspection is a major building
block for Industry 4.0
Optical inspection
systems, available
for all kinds of
materials from
board to tissue, can
make a significant
contribution to
increasing profits
and customer
satisfaction. This is not
limited to only a single
paper machine but, with
modern cloud solutions in
a network, for an entire worldwide
production. The greatest savings
potential can be realized from the
reduction of the number of web
breaks. Even a 20% reduction
saves an enormous amount or
increases the output of a paper
machine.
Figure 4: The fully integrated IntelliCam can detect web
breaks even in the roughest environments.
About the author:
Jorma Järvinen has spent over 30 years in the paper
industry on almost all levels. He started his career as a
laboratory assistant in a paper mill, followed by years working
with suppliers to the paper industry as an application and
service engineer. Järvinen then held various positions in sales
leadership before taking over the position of Business Unit
Manager for ISRA VISION´s paper business in July 2021.
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