ZTE Helps Eastman Develop Unique Fibers

By Cameron Walker

For the past six years, the Wilson College of Textiles has been working with Eastman in many exciting ways. One in particular has been to assist in the development and testing of two unique fibers through Zeis Textiles Extension: Naia™, a silky and luxurious cellulose acetate, and Avra™, a polyester with exceptional performance-enhancing capabilities. Naia™ recently debuted at international lingerie and activewear trade show Interfilière Paris, and Avra™ was recently incorporated into the base layer of the U.S. Ski Team’s official uniform.

“Eastman is collaborating with the school [because] we have the capabilities to assist them in processing the material,” said Jeff Krauss, Dyeing and Finishing Pilot Plant manager for Zeis Textiles Extension. “This is their chemistry, this is their fiber. We have the equipment in creating and spinning, in knitting and in wet processing to add value to their materials.”

The relationship was facilitated by Loren Chambers, commercial manager at Eastman since 2011. His previous employer, Milliken & Company, had a longstanding relationship with the Wilson College of Textiles, so he was already well-versed in the school’s capabilities.

“When I got here, I already knew what Jeff Krauss’ lab could do and what the Wilson College of Textiles could do,” said Chambers. “I reached out to Jeff and Brian (Davis) at that point to take advantage of the facilities they have, to do early testing…those guys are great. It’s easy to go to somebody who understands what they are doing and tell them what you want to accomplish.”

We are constantly striving to innovate new products to meet those demands in the marketplace.

Naia™

Naia™ is a comfortable, washable yarn with a silk-like aesthetic well-suited to the intimate apparel market. Eastman developed the product nearly a century ago and since then it has been used in a range of applications from medical tape to formal wear. However, the company has used recent improvements in manufacturing techniques to spin it into a lower denier yarn — making it finer and more lightweight — while also improving tensile strength. Over the past few years, they have researched the yarn’s properties in comparison with competitive materials.

“We discovered that value propositions for Naia™ fall into three categories, which are comfort, luxury and ease of care,” said Heather Quigley, applications development scientist at Eastman. “Around comfort, we found that Naia™ has very good dry rates…it has good moisture management and has a cool hand. In terms of ease of care…the fabrics are washable, they have good dimensional stability, good wrinkle recovery and good soil release as well…In terms of luxury, we have a very nice drape, silky hand and luster. It’s a very lustrous fiber, naturally.”

Knitting Lab manager Brian Davis experimented with mixing the product with other yarns, including cotton, polyester, nylon and spandex. Krauss took Naia™ through its paces — washing, processing, dyeing and finishing it — and proved the yarn had high stain resistance and was able to be richly colored. Weaving Lab manager William Barefoot wove the new yarn into prototype fabrics.

“This cellulosic yarn is made from renewable wood pulp harvested from sustainable forests and produced in a near-closed loop process in the United States,” said the company in a recent statement. “All waste is either recycled, reused or offered for resell. Also, solvents used in the production of Naia™ are recycled back into the system for reuse. Water returned to source streams is routinely tested to ensure the biodiversity of the local river is receiving clean water.”   

Avra™

Eastman’s new performance fiber is designed to be moisture-wicking, with a soft hand and a cool-to-the-touch sensation — but the component that makes these qualities possible is not actually a part of the final product.

“Avra™ is, for lack of better words, a super fiber,” said Chambers. “We use a proprietary sacrificial polymer to do bicomponent spinning to be able to knit a high denier and then open to a very low denier.”

Avra™ is a ribbon-shaped synthetic fiber so fine that it must be enrobed in a sacrificial polymer sheathing in order to be knitted or woven — much like the inverse of papier-mâché. The fiber and its protective sheathing are knit or woven into fabric together, then during fabric wet processing, the sacrificial sheathing is removed, leaving behind the finer inner core.

“The critical technology here is the bicomponent aspect,” said Dr. Richard Holbert, an application research scientist for Eastman and an NC State triple alumnus. “Bicomponent fibers are not necessarily new, but the special sauce is the sacrificial polymer that is proprietary for Eastman, (which) enables different wet processing techniques that make it a little bit easier to remove that polymer.”

In the Knitting Lab, Davis worked with the yarn in its pre-scoured phase, which presented some challenges along the way. In fact, the initial package of Avra™ yarn completely washed away during the first test knit.

“The filaments were sticking together,” said Davis. “I would start knitting and all of a sudden there was nothing there to be knit.” The company solved the problem and relied on the lab to trial knit as they worked on the spin finish and winding tension and extending the product’s shelf life.

In the Dyeing and Finishing Lab, Krauss noted how the fabric changed as he put Avra™ through the scouring process.

“When you wash and scour [a product], it is going to change its [properties],” said Krauss. “Then you have to go back [to the Knitting Lab] and change the knitting structure — trying to achieve that proper hand, that dimensional quality, that opacity, that you’re looking for.”

The way Avra™ is manufactured enables a smaller, more lightweight fiber than others on the market, which means it is engineered to enhance the wearer’s performance.

“The properties that the fiber enables are better moisture management, in terms of being able to wick moisture away from the skin and spread it further through the fabric,” said Holbert. “[This] also enables faster dry rates, so if you are actively running or hiking and you are perspiring heavily, an Avra™ fabric would be able to wick that moisture away from your skin faster and dry it faster so you feel more comfortable.  When you first grab and feel the fabric, it has an initial cooling sensation that you can feel and it does demonstrate a long term cooling performance over time — which is a major benefit for the active base layer market. That is where we are targeting and using the fiber, at least at first.”

The company is exploring future applications for Avra™ and experimenting with its technology.

“Our first product will be a flat-shaped polyester,” said Chambers. “But we have the ability to change shape, change size and change the polymer, so it will be a full platform for Eastman going forward.”

What’s next?

Avra™ and Naia™ are just the beginning of the collaboration between Eastman and the Wilson College of Textiles. The company has sponsored two senior design projects, one investigating the limitations around the production of crimped staple fibers and one designing fabrics that blend Naia™ with other yarns such as polyester and nylon. Along with the undergraduate efforts, Eastman also is currently sponsoring three doctoral level projects within the Wilson College of Textiles through their Eastman Chemical Center of Excellence.

Zeis Textiles Extension isn’t the only group in the Wilson College of Textiles working closely with Eastman Chemical Corporation. Faculty in the Departments of Textile Engineering, Chemistry and Science (TECS) and Textile and Apparel, Technology and Management (TATM) have worked with Eastman on numerous research projects in the past, and the Textile Protection and Comfort Center (TPACC) has ongoing work with them as well. The Wilson College of Textiles values a collaboration with Eastman, because working together will contribute to economic development in the United States and fill existing and future needs in the textile industry.

“We have massive efforts going on with our business team, reaching out to brands and mills and understanding what the unmet needs are in the textile industry,” said Quigley. “Brands and mills always want to know what’s new and what you are doing to innovate. We are constantly striving to innovate new products to meet those demands in the marketplace.”