Material innovation: Teaming up with its customer Temco, the Lead Center Fluid Power Industry is opening a new chapter in its business with the textile industry.
We are all familiar with sewn-on labels on jackets, shirts and pants. Along with washing and ironing instructions, they list the materials contained in the clothing items. Their look and feel give the impression that they are natural cotton. But a glance at the small cloth rectangle often reveals synthetic fibers such as polyester and polyamide. And that trend is on the rise.
Texturizing is the magic word in the field of synthetic fibers and their use in clothing. It describes a refining process that imparts a fluffy cotton-like structure, and related properties, to extruded smooth threads of artificial fibers. Here the Lead Center (LC) Fluid Power Industry, a unit of Freudenberg Sealing Technologies (FST), plays a crucial role in millions of instances throughout the world, especially in Asia. With its Temco brand, Rieter Components is the global market leader in texturing discs and the top customer of the Lead Center in Schwalmstadt in North Hesse. “Our cooperation with Temco dates back to the middle of the last century,” said Markus Webelhuth, Manager, Product Development, LC Fluid Power Industry.
Friction Is In Demand
Simply put, extruded synthetic fiber filaments resembling fishing lines are heated, mechanically twisted and stretched during texturing. That means they come out of the unit faster than they were fed into it. At enormous speed, the threads are conducted over several rotary running discs with rough surfaces as though they were on a slalom course. These rotating discs, called friction discs, come from FST.
To create them, the Lead Center in Schwalmstadt applies a polyurethane (PU) covering all around a circular plastic carrier part. The two components – carrier and PU – claw into one another mechanically. “We developed the PU especially for Temco, and we are continuing to improve it,” said Webelhuth. Initially, the discs’ lifespan was a few weeks. Today, they can function for two years.
In technical terms, the main challenge facing polyester is called avivage, an agent used to enhance the spinning process. Before being processed, polyester yarn is soaked in the agent. But it attacks classic polyurethane aggressively. To combat the problem, FST has identified a suitable material that withstands avivage. A slight swelling of the material compensates for the mechanical abrasion of the disc. When viewed through a microscope, the polyurethane surface that provides the traction has a so-called “orange peel” look.
A word about the magnitude of the business.: Four to six rotary discs from FST are at work in each of the Temco units. In a single texturing machine, there are about 2,500 of these units, bringing the total to 10,000 to 15,000 FST parts. In turn, each yarn producer has hundreds of these mega-machines. So it is no surprise that FST has been providing several million texturing discs just to market leader Temco annually.
Staying On Track
It could soon be even more. Until now, Temco has focused exclusively on the texturing of polyester, the most commonly used synthetic fiber in clothing. Thanks to a further development of FST’s polyurethane, the texturing disc can also be used for polyamide yarns. The impact on the business has been positive: In more and more textile machines, Temco friction discs from FST are replacing the ceramic discs currently in use for polyamide. Here as well, the “made by Freudenberg” PU discs are impressive for their convenient handling, good value for the money, and their robust, reliable performance over the long haul. That ensures high yarn quality.
“Avivage, which has been so challenging for our polyurethane, is not used with polyamide. But here we have another tough task,” said Thomas Weber, the Account Manager responsible for Temco at Sales General Industry. Without avivage, the disc’s initial roughness is polished smooth after just a few weeks of use. “It is as if you had put wet-weather tires on a Formula 1 car racing on dry pavement. After a few circuits, the tread and the traction are gone, and you slide out of the next turn,” Weber said.
But the Lead Center has also found a solution for this problem. It includes a tiny additive in the polyurethane – its exact nature is not being disclosed. These minuscule particles are not bonded firmly into the PU matrix. During operation, they break away and keep the surface from becoming smooth from the abrasion. “We maintain a surface that resembles a rough moonscape under the microscope and reforms again and again when there is more abrasion,” said Webelhuth. Field tests and comparative studies show a minimum lifespan of 24 months for the discs, which Temco markets as Nanodiscs.
“In addition to technical expertise, development work in the textile industry requires stamina over a period of years,” Weber said. “We have that, and it is starting to pay off with polyamide as well.” The approach is efficient and practical: The Lead Center can process the new discs for use with polyamide in Schwalmstadt, using the same tools that it uses for the standard discs for polyester.
So next time you are getting dressed in the morning and standing in front of a mirror, give some thought to a real possibility: The synthetic fibers woven into your clothing might well have come into contact with friction discs from Freudenberg.
