Fashion, and particularly so-called fast fashion, in which companies release multiple rounds of cheap clothing every year, takes massive toll on the environment. Fashion is estimated to account for about ten percent of human carbon emissions. The production of clothing has doubled just since the year 2000, and while people bought 60 percent more clothes in 2014 compared to 2000, the clothes they bought were only kept for half the average time.
This is an incredibly unsustainable practice. By the year 2020, textiles became the third largest contributor to water degradation and land use. Synthetic fibers also deposit huge amounts of microplastics into the environment. In the United States, 34 billion pounds of used textiles are tossed out every year, and 66 percent of those unwanted garments end up in landfills, where they sit, decomposing over lengthy periods of time.
Recycling these clothes is not possible right now because of the presence of elastane, an elastic fiber commonly used in clothes to make them stretch and adapt. This fiber is more commonly known as Lycra or spandex, and it is usually combined with cotton, nylon, wool, and other fibers to make material for clothes. While that makes the clothes more comfortable, it also renders them essentially impossible to recycle.
Scientists have now developed a method to separate the mixed fibers in some fabrics, and make them easier to recycle. The work has been reported in the journal Green Chemistry.
This method can completely remove elastane from nylon. Although the technique has not yet been perfected for use with cotton, some minor adjustments can probably solve the problem and make the process suitable for cotton too, said study co-author and Assistant Professor Steffan Kvist Kristensen of Aarhus University.
Nylon or cotton fibers are usually wound around elastane fibers, making very difficult to separate them. Since elastane is made up of long chains of molecules, the fibers only break up when these chains are broken, explained Kristensen.
This breakage can be done with heat and a type of alcohol that breaks the bonds in the elastane chain, which are made of diamine molecules. After cooking textiles in a pressure cooker, the fibers separate. This disassembly means more textiles can more be recycled, noted Kristensen.
Right now, the process has only been tested with nylon stockings and cannot be implemented on a large scale. To do so would also require the cooperation of partners in the chemical industry.
“If we’re to succeed with this, we need to get the large chemical plants on board. But they must see a business model in buying recycled materials and using them in the production of new fibers. If they don’t, the technology will never take off," Kristensen noted.
Sources: Aarhus University, Green Chemistry