The Urethane Blog

Bio Route to Spandex Fiber

They could have just used furfural based PTMEG . . .


Invista says market is slowly warming up to biobased Lycra fiber

By Karen Laird
Published: April 16th, 2015

Invista (Wichita, KS) takes sustainability seriously. The company established its Planet Agenda sustainability program some years ago, with the aim of developing and marketing competitive products with an enhanced environmental performance and that used fewer resources while meeting the needs of the apparel markets. In line with that aim, Invista last year announced the development of a bio-derived spandex yarn that would be rolled out globally for the autumn/winter 2015 and spring/summer 2016 apparel collections.

Invista"Once the technology became available to do so, we decided we should investigate the possibilities of producing a bio Lycra," said Arnaud Tandonnet, Invista Apparel Global Sustainability Director, at the International Conference on Bio-Based Materials in Cologne, Germany, this week. "It wasn't so much because of demand from our customers—we did it more as a logical step on the path toward fulfilling our stated commitment to sustainability. And that includes developing products and technologies that help our customers achieve their sustainability commitments."

The project involved a 2 ½-year development process. "We produced the fiber in our research facilities and evaluated it carefully in fabric applications," said Tandonnet. "We tested the way it performs during processing. And we can say: There is really no difference."

Approximately 70% by weight of the T 162R Lycra bio-derived spandex fiber comes from a renewable butanediol raw material source made from dextrose derived from corn. Invista uses bio 1,4-butabediol made using technology developed by Genomatica. Genomatica successfully developed a fermentation route to the chemical in 2008 using genetically engineered E. coli bacteria to metabolize sugars into 1,4-butanediol.

"The 1,4-butanediol is synthesized into the intermediate molecule THF, which is used to make polytetramethylene ether glycol, or PTMEG," explained Tandonnet, "PTMEG makes up 70% of the spandex fibers."

Now that the first commercial quantities of the new product have entered the market, the obvious question is: How has the market responded?

"Customers are still warming up to the idea," said Tandonnet. "While they like the idea of a more sustainable material, we have had to explain that substituting bio-BDO for conventional BDO makes no difference to the final product. The molecule is exactly the same—just the feedstock is different. But they are cautious."

The company is marketing the bio spandex as a specialty product, he added, so compared to conventional Lycra fibers, there is a small premium. However, the use of a renewable feedstock in making the new fiber results in a lower CO2 and fossil fuel emission footprint than spandex produced using traditional raw materials.

"The development of our bio spandex was due to our willingness to make the commercial bet. We are waiting for scale, but we really wanted to be on the train before it left the station," said Tandonnet. "The fact that we can offer a biobased fiber we see as a unique selling point."

Invista is currently examining the possibilities of developing a 100% bio spandex fiber, and is also looking at some of the other polymers in its portfolio for which biobased versions can be developed.