By J. Michael Quante, AATCC science editor
Greater than the Sum of its Parts…
Creating fabrics with fiber blends is a mainstay of our industry, combining fabric properties that can lead to greater wearability, durability, easy-care properties, affordability, and multi-functionality (e.g., athleisure wear). Leading the pack by a wide margin are cotton-polyester blends (or polycotton), combining the number 1 (polyester) and 2 (cotton) most produced fibers worldwide into fabrics. By adjusting the ratios of these fibers, fabrics can be produced with many attractive properties that balance breathability and comfort, as well as launderability. Both consumers and industry have greatly benefited from the marriage of these heavyweight fibers. But, every silver lining has its cloud…
…Especially Recycling Problems
With the current emphasis on sustainable textile manufacturing, the issue of what to do with polycotton fabrics at their end-of-life stage is a thorny one. Separating cotton and polyester from these blends, while retaining each fiber’s ability to be separately recycled, has been a challenge facing the industry for some time. Much research effort has only recently begun to bear fruit with regards to scalable industrial processes.
Apples and Oranges?
Comparing cotton and polyester is much like comparing fruit and decorative waxed fruit. Both are fibers, but one is natural and the other, synthetic. Cotton is hydrophilic (water loving) and polyester…not so much. The chemistries and physical properties of the two are very different. This, to some degree, is an advantage, but only if the conditions are such that BOTH materials can be recycled after untangling them. This is the conundrum that the industry faces, and it is not an easy one to solve.
Forestry Leads the Way
Recently, much of the leadership behind polycotton recycling has come from Scandinavian forestry. Much of this is due to efforts to preserve their valued forest resources. In Sweden, Södra, a forestry cooperative, has introduced a way of separating polyester from cotton, with the recycled cotton reused in wood pulp. In addition, they are investigating ways to reuse the polyester in fabrics. Only undyed polycotton can be recycled at present. Commercialization and further research are underway, with a long-term goal of producing 25,000 tonnes of wood pulp.
The VTT Technical Research Centre of Finland and their academic partners are actively pursuing blended fiber fabric recycling as well. The Telaketju network, promoting sustainable textile recycling, is now in the second phase of their research into making the circular textile economy a viable business model.
One approach is tackling another fundamental problem: how to identify and properly pre-sort various kinds of fabrics. Infrared sensing technology can help speed up the manual fabric sorting process. Phase two’s goal is to turn end-of-life textiles into high-quality textile products.
In the United States, Tyton Biosciences is creating technology for generating pulp and petroleum monomers from polycotton and other recycled fabrics to replace use of virgin materials. It has just raised US$8M to further bringing this new process to market.
What Comes Around, Goes Around
Our ancestors knew the value of resource renewal and reuse. It just makes good sense in a world of limited resources to make the most of what we produce, buy, and use, including our fabrics. The textile industry is beginning to realize the exciting and profitable opportunities recycling blended fabrics can provide. What is your company’s sustainability story?