Can Cotton Close the Loop?
As environmental awareness grows in response to high-profile issues such as climate change and pollution, sustainability has become an increasingly important issue. Environmental sustainability means adopting practices that don’t deplete our natural resources or harm the ability of future generations to meet their own needs.  For the textile and apparel industry, sustainability involves not only conserving water, energy, and chemicals at every stage of textile production, but also reducing waste and minimizing environmental pollution when a textile product reaches the end of its useful life.
Historically, manufacturing systems have followed a linear “take, make, and waste” model — meaning that raw materials are taken from the earth, made into products, and disposed of as waste, taking up space in landfills or polluting the environment. Textile products make a significant contribution to the U.S. waste stream, accounting for 8 percent of municipal waste sent to landfills.
Plastics in particular follow the linear “take, make, and waste” model. Oil is extracted from the earth and made into plastic polymer, which is used to manufacture products. Then, once a plastic product is discarded, it persists in the environment, because conventional plastics (99.7 percent of all plastics produced) are not biodegradable. Though Americans have been sold on the importance of recycling plastic, recycling has barely made a dent in the plastic waste problem — less than 9 percent of plastic produced in the United States is recycled, while over 75 percent ends up in landfills. Worse yet, plastic waste can break up into microplastic particles, which are now found throughout the environment and even inside living organisms. And the most common source of microplastics? Plastic microfibers shed by synthetic fabrics.
In contrast to the linear model, circularity is an approach to reducing the environmental impact of textile products at the end of their useful life by reusing them, recycling them, or returning them to the earth. Circularity is best achieved by designing and manufacturing products in ways that make reusing, recycling, or returning them as efficient as possible. According to Dr. Jesse Daystar, vice president and chief sustainability officer for Cotton Incorporated, the goal is to create a “circular economy that is restorative and regenerative by design, and aims to keep products, components, and materials at their highest utility and value at all times.” A circular economy mimics the cycles of nature. As a renewable biological product, cotton is ideally suited to a circular economy.
Reuse, Recycle, Return
Cotton’s natural durability gives cotton textiles a long life — instead of being discarded, clothing and home goods often enter the secondhand market or are repurposed. Manufacturers and product developers can help meet circularity goals by intentionally designing for durability to extend product life.
Most communities can’t accept textile waste directly from consumers for recycling, but the apparel industry is actively developing programs to recycle both pre- and post-consumer cotton textile waste on a commercial scale, as discussed below. Brands can also design for recyclability, to make it easier and more cost-effective to recycle cotton textiles into yarns, fabrics, nonwovens, and an array of non-textile products, such as insulation, filters, automotive uses, and even 3D printing and injection molding.
As a biological product (cellulose fiber), cotton is naturally biodegradable. Textiles made of 100 percent cotton can potentially be returned to the earth to decompose. In studies, cotton microfibers in wastewater were 76 percent degraded in 250 days, and composted 100 percent cotton fabric was degraded up to 77 percent in 90 days. Brands have even recently introduced the first fully biodegradable denim apparel.
Traditional Recycling of Cotton
Recycled cotton commonly comes from pre-consumer waste, such as fabric cutting scraps, and is recycled by mechanical processes. Mechanical recycling involves shredding the waste fabric, separating the cotton fibers, cleaning them, and spinning them into new yarn. Based on Cotton Incorporated’s experience, the main limitation of mechanical recycling is that it yields relatively short fibers, reducing spinnability and resulting in lower-quality yarns and fabrics. So recycled cotton often is blended with other fibers, usually at no more than 20 percent of the fiber content. Another limitation is that only 100 percent cotton textiles can be mechanically recycled — not blends — and non-cotton components of products must be removed. As a result, uses of recycled cotton are limited by cost, availability, and quality constraints.
Mechanically recycled cotton is well suited for use in products made from nonwoven textiles, such as wipes, furniture padding, bedding, and hygiene products. Researchers are also exploring the use of recycled cotton fibers to reinforce composite materials — cotton fibers have been combined with a polymer matrix, replacing synthetic reinforcing materials. Waste cotton has also been turned into a cellulose gel that can be used as a 3D printer “ink” or combined with other materials to be molded or cast into forms to create innovative materials with special properties.
An exciting nontraditional use of recycled cotton is as insulating material for a variety of applications, such as building insulation and cold-chain shipping. Some of the denim insulation used in shipping of perishable food is supplied through Cotton Incorporated’s Blue Jeans Go Green™ initiative, which partners with brands and retailers to collect worn denim apparel with at least 90 cotton content for recycling.
Promising New Recycling Technologies
New recycling technologies hold the promise of producing higher-quality recycled cotton yarns and fabrics and of being able to handle blends and post-consumer waste. Researchers and manufacturers are working on methods for chemical recycling of cotton textiles, based on turning cotton waste into cellulose solutions that can be extruded as fibers (a process similar to manufacturing viscose). These processes mostly involve combining recycled cotton with other sources of cellulose, such as wood pulp. Some processes can even chemically separate cotton/polyester blends into cellulose and polyester. A goal is to increase the recycled cotton content of textile products without compromising quality.
It’s estimated that of the 13.1 million tons of textiles sent to U.S. landfills or incinerated, 35 percent is currently recyclable, and another 45 percent could be recycled with advanced technologies. Commercial-scale U.S. trials are planned to demonstrate the feasibility and value of currently available recycling processes, with the goal of promoting the establishment of cost-effective circular textile supply chains.17 Improving and integrating textile recycling technologies, both mechanical and chemical, can help to keep textile waste out of landfills and transform it into “new” raw materials.
Towards a Circular Economy
The goal of reaching a sustainable balance with nature has spurred exciting developments towards the goal of a circular economy in the textile industry. However, as Dr. Daystar points out, circularity does not equate to sustainability — it is a means to sustainability. The environmental impacts of circular practices still need to be measured to confirm whether they are truly beneficial. But cotton’s durability and biodegradability make it naturally suited to circular solutions. Recycling cotton textiles, especially blends and post-consumer waste, poses challenges, but research and development to overcome these challenges are ongoing, as manufacturers and brands commit to improving and scaling up cotton recycling technologies.
Who We Are
Cotton Incorporated is the research and marketing company for U.S. cotton growers and importers. Established in 1970 as a not-for-profit company, its mission is to increase the demand for and profitability of cotton. The company meets this straightforward mission by identifying efficiency and best practice opportunities along each link of the global cotton supply chain, and through global marketing efforts aimed at consumer and trade audiences.
Cotton Incorporated’s CottonWorks™ program is an extension of its global education and marketing efforts. This comprehensive online resource provides textile professionals and students with the essential fiber-to-fashion knowledge, expert problem solving, up-to-date research, and inspiration needed to navigate the future of cotton and textiles.
To Learn More
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1. University of Alberta (2021). What Is Sustainability?
2. EPA (2019). Textiles: Material-Specific Data.
3. Science Advice for Policy by European Academies (2020). Biodegradability of Plastics in the Open Environment.
4. Sullivan L (2020). How Big Oil Misled the Public Into Believing Plastic Would Be Recycled.
5. EPA (2021). Plastics: Material-Specific Data.
6. Hale RC, Seeley ME, La Guardia MJ, Mai L, Zeng EY (2020). A global perspective on microplastics. JGR Oceans 125:e2018JC014719.
7. EPA (2020). What You Should Know About Microfiber Pollution.
8. Ellen MacArthur Foundation (2021). Redesigning the Future of Fashion.
9. Cotton Incorporated (2019). How Quickly Do Textile Microfibers Degrade in Aquatic Environments.
10. Li L, Frey M, Browning K (2010). Biodegradability study on cotton and polyester fabrics. Journal of Engineered Fiber and Fabrics 5(4):42–53.
11. TheIndustry.Fashion (2020). Lee Jeans Launches “Back to Nature” Collection, a Fully Biodegradable Denim Capsule Collection.
12. Cotton Incorporated (2021). Recycled Cotton.
13. Bajpal SK (2015). The use of cotton fibers as reinforcements in composites. In Biofiber Reinforcement in Composite Materials. Faruk O, Sain M, eds. pp. 320-341
14. Latzke JM (2017). The future fabric of our lives. High Plains Journal.
15. Cotton Incorporated (2021). Blue Jeans Go Green™.
16. Hugill R, Ley K, Rademan K. (2020). Coming full circle: Innovating towards sustainable man-made cellulosic fibres. Fashion for Good.
17. Accelerating Circularity (2021). Putting Textiles to Good Use.