While many don’t give much thought to tire yarns, relentless process improvement and exceptional machinery are delivering safer, more durable, and lighter-weight options for partners and consumers.
By Gwen Moran
Many people think of tires as being made from durable slabs of synthetic material. However, they don’t realize that material is made from many high modulus, low shrinkage (HMLS) yarns that are manufactured into the familiar forms that move our vehicles along the world’s highways, roads, and other surfaces and terrain.
However, creating these versatile, durable industrial fibers is no easy feat. Tire manufacturers demand increasingly more durable materials that maintain their stability in extreme temperatures and in rigorous use. Doing so requires innovation at every level of the manufacturing process—especially in tire cord production.
The high temperatures and fast speeds at which polymer materials need to be melted and spun require specialized, high-performance machinery to deliver fibers that are sufficiently tear-resistant, but elastic and temperature as well as dimensionally stable. The higher the spinning and winding speeds, the more sensitive the filaments respond to even the slightest irregularities in polymer melt, possibly resulting in breakage that can affect quality. Oerlikon Barmag is one of just two companies worldwide that deliver machine solutions for the production of HMLS yarn.
“HMLS yarn machines are ‘champion’s league’ among industrial yarn machines,” says Markus Reichwein, Oerlikon Barmag’s Head of Product Management. The machinery components must remain stable under punishing conditions. In addition, process engineers must continuously optimize the spinning process from melt to yarn to meet customers’ high expectations.
As a result, Oerlikon’s machines are able to achieve the world’s fastest spinning process with speeds of around 6300m/min and temperatures reaching as high as 260°C. In addition, the team intensively reviews product performance at every stage of the tire cord manufacture—including, twisting, weaving and dipping—to ensure that the final treated fabric meets rigorous standards and to identify possible process and machine improvements, adds Roy Dolmans, Team Leader of Industrial Yarn Process at Oerlikon Barmag.
“With our latest developments it is possible to process higher polymer viscosities at lower temperatures,” Dolmans says. The result is a moderate treatment that produces a thicker polymer melt, improving the material’s tenacity and stability. In other words, tougher materials from which to make tires.
Just as constant innovation leads to improvements in manufacturing processes and outcomes, it also has an impact on sustainability. Customers want to know that their manufacturing partners have environmentally sound practices. Oerlikon’s EvoQuench manufacturing process reduces the air volume necessary to solidify molten filaments. In addition, the use of high-frequency heating coils inside some components lead to less energy loss while heating the yarn faster and more precisely than conventional heating technology.
As the market shifts, both Dolmans and Reichwein say that there is a strong push for process automation to minimize labor costs, improve efficiency, and increase yarn quality. Tire manufacturers are looking for more durable fabrics that can manage the same load at a lower weight. Through process improvement and digitization, companies like Oerlikon Barmag have greater methods of handling, visualizing and analyzing data to improve efficiency and save money while delivering on customer expectations.
Achieving those varied facets of improvement “requires not only a very high competency and accuracy in designing and manufacturing the machines, it also requires deep HMLS process know how to exactly define the correct hardware specification as well as also the required process settings,” Reichwein says. When achieved, it is the consumer who ultimately benefits from an affordable, exceptional product, sustainably produced.