Retech Godet rolls made to meet topmost
The popular phrase ‘hanging by a
thread’ really means something in yarn applications for
protective wear, as well as in medical, automotive and aviation.
Man-made fibers for these sectors have to fit specifications
precisely, to be on the safe side for both producers and
end-users – and Retech develops godet rolls as the key
manufacturing components to ensure these standards are met.
These threads – some literally life-saving – are made of
polyamide, polyester, polypropylene, aramid, carbon, bio-based
and many other polymers, categorized as technical yarns and
high-performance fibers. Retech launched two innovative godet
rolls lately: the Ø 250 mm model developed for technical yarns
and the Ø 320 mm model, reaching out to today’s temperature
conditions, as needed for high-performance fibers such as aramid.
High-tech for a secretive business
Yarn engineering is a secretive business when it comes to
sensitive applications, as well as future developments.
Customers build on Retech expertise and trust its wide range of
key components in perfectly meeting requirements such as
temperature, speed and torque. But only in rare cases does the
customer provide any information about the yarn and its final
characteristics. “Comparing required customized solutions shows
us trends regarding the market demand for godet rolls. It
becomes our ambition to innovate the one godet roll meeting
these latest customer needs,” says Ralph von Arx, CEO, Retech
Identifying a strong demand for technical yarns with maximum
strength, Retech addressed this with the newly-launched type Ø
250 mm roll, with an ideal length of 420 mm to process eight or
twelve threads at a time. The extended diameter of 250 mm allows
a significantly higher speed with the same dwell time.
Additionally, the higher motor torque guarantees the very best
results in yarn tenacity.
Further technical parameters are as remarkable:
speed can be ramped up to 6500 m/min – applying a torque value
of 15 Nm through the full speed range – and the temperature
reaches 250°C with an excellent temperature profile of +/- 1.5°C
over the whole working width of the godet roll. When comparing
its performance with the popular type of Ø 220 series, the
achievements become even more impressive, since the speed can be
increased further, as well as the torque. These differences make
it possible to process a much wider range of yarn counts.
Retech Godet Roll 320 mm.
Reaching to the limits of strength
Retech has built a strong reputation for using technology
enable a larger diameter and the required heating capacity
within limited space. The new type Ø 320 mm, specially developed
for high-performance fibers, has become Retech’s latest pride.
Featuring various length, this type is ideal for serpentine yarn
paths to multi-enlacement, and suits practically all machine
concepts and yarn paths. For high-performance fibers it’s
essential to optimize heat entry into the yarn, so the first
step must be to extend the dwell time, which in turn is
influenced by speed and diameter. The top diameter of Ø 320 mm
allows the number of revolutions per minute to be reduced,
resulting in optimum dwell time – while taking the advantage of
an enlarged contact area. Unique yarn characteristics are made
possible by impressive temperatures up to 400°C, along with
torque values of 35 Nm and speeds up to 1500 m/min.
Aramids are today the strongest textile fibers. Para-aramids
generally have high glass transition temperatures nearing 370°C.
Heat treatment under tension increases crystalline orientation
for unique tension values – all perfected when mechanical
drawing orients the polymer chains in the fiber direction. For
two reasons, the Ø 320 mm model is the ideal godet to produce
sophisticated products such as aramids: it meets technical
requirements for heat, torque and speed and it performs at the
required precision. Retech’s reliability in use is founded on
precise temperature measurements and adjustments – a major
aspect of continuous developments.
Until the ultimate
Committed to constant innovation and improvement, Retech
engineers have already worked on perfecting the new generation
of temperature transmitters successful launched at ITMA 2019.
Changes in the temperature control of the individual induction
heater zones have improved power input and load distribution.
More uniform power input into the inductor reduces the pulsation
of the induction heat and prolongs the lifetime of the induction
heater itself, as well as of the motor bearings. The
smooth-running high-precision drives become even smoother, which
brings significant advantages. For example monofilament,
producers are able to make yarn of finest titer without the
slightest variation in diameter. Last but not least, the changes
additionally have a positive effect on the power grid, making
its utilization more even, with fewer peaks, and facilitating a
more balanced running of the mill’s system load.
The culture of ongoing enhancement and the desire for
perfection make Retech a reliable partner when it comes to yarns
for challenging – and especially life-saving – applications.
“Producers can rely on us. We never stop until we can draw our
customer’s fibers to perfection,” says von Arx.