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The Textile Magazine
DECEMBER 2011
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121
while in a control zone, above the defined threshold. If
not, Maestro will stop the loom for weft breakage.
Another feature of the new Maestro System allows
the weft pattern information to be linked with the sig-
nal processing of the numerical values provided by the
weft detector. This is completely automatic, requiring
no technician intervention. What does this mean?
- If the weft of one eyelet position has to be inserted
and for some reason another weft is inserted, Maestro
will detect this and stop the loom.
- If two wefts are to be inserted and for some reason
only one or three wefts are inserted, Maestro detects this
and the loom will be stopped.
- If two wefts are to be inserted and for some reason
one of the two wefts is the wrong one, Maestro will de-
tect this and stop the loom.
- The same applies for any other wrong insertion, be it
a triple or quadruple insertion, in every case. If the sig-
nals transmitted from the weft detector are inconsistent
with the weft pattern, Maestro will stop the loom.
Because of this functionality any malfunction of the
weft selector or any case where a weft yarn gets en-
tangled with a neighboring weft, Maestro will stop the
rapier loom. Clearly Maestro is a further step in the di-
rection of a rapier weaving machine which guarantees
perfect fabric quality.
Some further words concerning the definition of the
thresholds, which can be set individually for each eyelet.
For a fine weft yarn count, the numerical value will be
lower than for a course yarn. If the technician wants to
weave with minimum weft yarn deflection (weft yarn as
much as possible in a straight line) the numerical values
produced by the weft detector will be lower. Maestro
visualizes these values and illustrates the weft insertion
curve on the loom’s display.
The technician can easily define the individual thresh-
old for each weft yarn in such a way that every weft
break will be detected without creating false or unwant-
ed weft stops. The insertion curves also allow the tech-
nician to have a clear view of the signals received at the
end of the weft insertion. This allows him to weave with
the longest weft control zone.
What is meant here is that the yarn will be monitored
to the point the weft is released from the gripper. This
feature certainly serves to eliminate defects for short
picks while also preventing false stops. Further, a more
controlled and precise release from the gripper is as-
sured. Consequently, the Maestro System also reduces
weft yarn waste.
With Maestro, ITEMA introduced a new look at weft
monitoring and the detection of weft breakages on ra-
pier looms. Thus, the complexity for the technician is
removed and handled by the software operating with the
micro-processor of the weaving machine.
Without adding cost to the weaving machine, the Sil-
ver 501 rapier loom assures better quality with Maestro
in charge of weft detection.
w
Fig 3: There are 2 zones where the weft insertion is checked
by the software. The settings are easily entered and prede-
termined on the touch screen for all positions (1 up to 12).
Fig 4: The weft sensor transmits at high speed for all posi-
tions of the sensor signal. This signal clearly illustrates how
the weft is transferred through the shed. The green line and
arrow indicates the threshold setting. If the weft signal drops
below the threshold in one of the zones in which the weft has
to be checked, the weaving machine will be stopped.
technology