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The Textile Magazine
DECEMBER 2011
Osthoff
hairiness tester, paving
way for efficient singeing
technology
ess to reduce the fabric hairiness.
The scope of supply consists of
a monochrome CCD camera and a
light source LED along with a guide
roller and necessary synchroniza-
tion with PC. This system consists
of a light source (LED) and a mon-
ochrome CCD camera. The light
source is slightly tilted, which illu-
minates the fabric surface tangen-
tially, so that the camera does not
register the shadows of the protrud-
ing fibres, but the refracted light.
This type is called dark field meas-
urement, because the background
remains black, whereas the objects
are shown bright.
Camera and light source are in-
stalled in a dust and waterproof
enclosure (IP67). The lenses of the
camera are protected by scratch-
resistant sapphire glass. Both parts
of the unit feature air nozzles, which
keep the optics dust free.
The camera signal (up to two
cameras are possible) is sent to an
industrial PC via Gbit Ethernet ca-
ble. The industrial PC is located in
the main cabinet and runs an analy-
sis program, which determines the
bottom limit (fabric surface) and
top limit (topmost visual point of
hairs) of the fibres. The distance in
between is the length of the hair. Af-
ter this, a variety of statistical data
is calculated; where for the evalua-
tion of the hairiness the mean value
and the standard deviation are used.
Fabric hairiness refers to
protruding fibres on a tex-
tile surface. These protrud-
ing fibres vary in length,
based on the quality of the
yarn used for weaving.
Due to these protruding fibres, the
final fabric surface can be rough.
This is often not in line with the
customers’ expectations. When-
ever such a fabric is dyed, then due
to the presence of these protruding
fibres, the colour appears hazy and
dull. This is due to the fact that the
protruding fibres act as obstructions,
and thus the angle of reflectance is
poor, thereby affecting the fabric
feel and quality.
How is hairiness controlled? It
is well known that the process of
singeing fabric is the best way of
reducing its hairiness. For example,
Osthoff Senge offers the famous
double jet burner, which with gas/air
mixtures, singes away the protrud-
ing fibres, thus offering a very clean
surface and soft feel to the fabric.
In addition, Osthoff now offers the
Osthoff senge hairiness tester. This
accessory allows an objective meas-
urement of the hairiness of a fabric
sample, which in turn lends itself to
proper control of the singeing proc-
Mr. Joerg Schlageter, Sales Director, Osthoff Senge and Mr. G. Elango of ATE