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Political uncertainty has caused
world economics to stagnate over recent months. End consumers have reacted
with reluctance in purchasing but, at the same time, still want to follow
fashion trends at acceptable prices. This means the textile industry has
to utilize saving potentials with a simultaneous increase in creativity
and speed.
This also forces weavers to re-evaluate existing filling insertion systems
in order to meet the various criteria such as creativity on the one hand
and, on the other hand, fast, reliable style changes as well as small
yardages from a wide range of yarns, and this without faults. Short
delivery times prevent reworking defective materials. DORNIER’s strategy
over many years has been that positively controlled rigid rapiers
represent the most reliable filling insertion system and that the Air-Jet
machine with its new technology is the logical supplement.
Mechanical filling insertion systems, such as flexible rapiers or
projectiles, usually require guide elements over the complete reed width
with corresponding higher friction as speeds increase and thus increased
heat development and wear. In comparison, DORNIER rigid rapiers run with
rolling friction at just 1/5 of sliding friction as shown in the relevant
technical literature.
Even experts find it hard to decide which guide system is best for
flexible rapiers in particular applications. Using guide teeth means
accepting reed marks and filament damage and working without guide
elements leads to more yarn breaks in the selvedge area and overruns
caused by asymmetrical rapier entry in the weaving shed. This seriously
restricts the flexibility, productivity and reliable quality required by
versatile, internationally active weavers producing a wide range of
styles.DORNIER carbon rapier rods combined with the
specified machine design run without disturbing the lower shed and their
extreme bending and tensile rigidity allows a precise transfer position in
the middle. Guide elements in the shed - even for wide machines - are
therefore not required on DORNIER machines. This opens up universal system use because there is practically:
• no restriction in warp density
• no restriction in warp material use
• no warp streakiness
• no filament damage to unentangled or flat yarns
• no seasonal change of rapier guide elements or rapier heads and therefore
• no time-consuming readjustment of shed settings.
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| Open-shed filling insertion on
DORNIER Rapier Weaving Machine
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Open-Shed Filling Insertion
Another decisive advantage of the DORNIER design is
open-shed filling insertion. The two catch selvedges bind the inserted
filling thread after the exit rapier has come to a standstill. The thread
is only now released and the shed closed. All this is performed under
absolutely controlled conditions.
The advantage is that all filling
materials are inserted independent of shed closing and inserted
contact-free through the weaving shed. Elastic filling threads can remain
free of tension in the weaving shed which results in excellent final
fabric quality, especially for highly sensitive piece dyes.
To summarize, the following advantages result from this technology:
• all filling threads, whether elastic, coarse or fine have the same
insertion length
• filling thread length is then only determined by the arrival of the exit
rapier which is opened when at a standstill
• shed closing and warp tension have no relevant influence on filling
thread length.
Negative flexible rapiers have a very high overstroke
on the exit side and therefore release the thread at high speed. This means
that all parameters such as shed closing, interlacing, warp tension, brake
setting and elasticity of the filling thread influence the thread length.
This leads to different filling thread tensions especially when processing
elastan yarns and results in thick and thin places in the fabric which
only become visible as faults after dyeing and therefore decisively affect
the quality of piece-dyed elastan fabrics. What is more, these weavers
normally stock large quantities of unfinished goods and customers only
specify their color wishes when ordering.
Constructions controlling the exit rapier opening time cannot correct this
error because an open shed system is still not used so that the filling
thread is tensioned in the shed.
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| DORNIER rapier rod air guidance, type
AirGuide™ |
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Patented Air Guide for DORNIER Rapier Elements - AirGuide™
The technically perfect solution for guiding mechanical
elements is the contact-free form of the aerostatic bearing. The
straightness of DORNIER’s rigid rapier offers ideal conditions for this
"air cushion guide". A guide plate which directs air to the rod replaces
the existing guide rollers. The plate also has a temperature monitor which,
for the first time, provides automatic self-control on mechanical
filling insertion systems. This opens up a new dimension in process
reliability for users and provides a decisive technological lead for
positive rigid rapiers.
Further advantages are:
• rod cooling by the air guide means longer lubrication
intervals
• reduction in maintenance costs by doubling the service life, thereby
• improvement in efficiency and reduced personnel workload
• self-cleaning effect and therefore production of clean fabrics
• fail-safe characteristics.
The AirGuide™ has been available on request as from the
4th quarter of 2002 and can be retrofitted on all P types. Please consult
our Customer Service if you wish to retrofit older Rapier machine types.
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Insider IMPRESSUM
Publisher and copyright:
Lindauer DORNIER GmbH
D-88129 Lindau
Telephone: ++49 83 82 70 30
Telefax: ++49 83 82 70 33 86
E-Mail:
webmaster@lindauer-dornier.com
Editor:
Egon Wirth
Graphics und realization:
Sutter Design Identity, Zürich
Print:
REPRO-TEAM GmbH, Weingarten
Issued:
Once a year, edition February 2003
Reprinting:
Permitted only with our previous written consent, even for extracts.
Printed in Germany
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