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 is the expert, backed by over 45 years of experience, in heat treatment and drawing man-made fibers of any material. The Swiss company 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
“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 AG.
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.
Reaching to the limits of strength boundaries
“We continuously touch today’s technical limits and stretch to tomorrow’s possibilities when developing. We take the risk, and try to optimize at the edge,” says von Arx. The new type Ø 320 mm, specially developed for high-performance fibers, has become Retech’s latest pride, and evidence of its efforts to support today’s yarn engineering ideas.
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.
Until the ultimate
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
