RESEARCH AND DEVELOPMENT
Tested: OnV FlocSpotter already successfully measures the formation at the headbox at
Voith Paper Technology Center in Heidenheim, Germany.
Uniformity right from the start
OnV FlocSpotter measures formation
already on the forming wire
The latest image-processing innovation from Voith Paper Automation is the OnV FlocSpotter. This is the first system that enables the
evaluation of the paper web uniformity already in the wire section.
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26 I 2008 I Voith Paper I twogether
RESEARCH AND DEVELOPMENT
Formation is one of the most
a camera delivering high-resolution
comparison of the formation values
important quality parameters in the
data at a shutter speed of less than
for different machine operational
papermaking process. It is decisive
10 microseconds had to be found for
statuses by operators. The program
for constant paper quality, since
the OnV FlocSpotter.
enables a visual representation of
fluctuations here have an effect on
the formation to be linked to the
a number of other parameters.
For the sake of comparison: This is
respective operational status. There-
Accordingly, sufficient strength and
faster than an electrostatic flash
fore, the formation can be optimized
good printability are only obtained
discharge. To ensure adequate expo-
in a targeted way during production.
with very uniform paper. Voith has
sure at such a short shutter speed,
now succeeded in developing a sen-
OnV FlocSpotter was equipped with
sor that already measures the forma-
a powerful LED illumination system
tion on the forming wire. This enables
(Fig. 2). The OnV FlocSpotter
the papermaker to intervene in and
camera housing was also adapted to
Infobox: Formation
regulate the process at the earliest
the harsh conditions of the wire
possible stage: after sheet formation.
section. It was designed to prevent
In the production of multi-ply pro-
accumulation of dirt particles.
Uniformity of paper web determined by
distribution and alignment of fibers in the
paper.
ducts, it also enables to determine
reliably the formation of individual
Thinking software
Contact
layers (Fig. 1). This is not possible
with the so far common formation
With the help of a software program,
measurement at the reel.
the images taken by the OnV
Dr. Armin Bauer
Automation
[email protected]
FlocSpotter can be classified into
Faster than lightning
familiar formation categories
Rudolf Münch
Automation
[email protected]
(e.g. normal, coarse, and fine) and
To enable the formation to be
evaluated. Together, these recorded
measured at speeds of more than
images form a “formation map” that
1,700 m/min (nearly 5,600 feet/min),
can be used for rapid and simple
coarse
white
points
normal
fine
Fig. 1: On multi-ply cardboard machines,
measurements can be made on the different
headboxes.
26 I 2008 I Voith Paper I twogether
Fig. 2: Good exposure performance is
achieved thanks to LED flash system.
Fig. 3: The formation map puts the current
measurement (red field) into a historical
perspective.
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