Two studies, published at the start of this year, open new ways for tackling one of the most pressing issues in the textile industry: the separation of plastic components from mixed fabrics.
In the textile sector, and particularly within fashion, sustainability and circularity are significant challenges.
We’re talking about an industry that’s pretty heavy on the environment, largely due to overproduction and excessive consumption.
The numbers don’t lie. According to what the United Nations Environment Programme (UNEP), Global Fashion Agenda, and Ellen McArthur Foundation have found, the world churns out about 92 million tonnes of textile waste every year, with 20 million tonnes of that in China and 17 million in the US.
If 92 million tonnes doesn’t quite paint the picture of how big the problem is, think about this: clothes and textiles take up at least 7% of all the junk in the world’s landfills.
And yet, every year, we keep making between 80 and 100 billion new pieces of clothing, which will eventually pile up into a huge mountain of textile waste, spinning in a cycle that’s far from good.
Here’s the kicker: 87% of the materials and fibres we use to make these clothes end up being burned or buried in landfills, only 20% of thrown-away textiles are picked up for being reused or recycled, and a measly 1% of clothes get recycled into new ones.
Most recycled fabrics get turned into lower-quality stuff. Moreover, over half of all the textile materials are synthetic, made from plastic fibres like nylon, acrylic, and polyester, which play a big part in the microplastic pollution problem. Also, something we don’t talk about much: every time we wash a synthetic piece of clothing, it sends plastic microfibres into the water. We’re talking about hundreds of thousands of tonnes of microplastics ending up in the oceans every year, with nearly 60% of the trash in marine environments being non-biodegradable clothing fibres.
TAKEAWAYS
The challenges of practising circularity in the textile industry
According to The Sustainable Fashion Forum, numerous hurdles remain to be overcome, despite growing consumer interest in sustainability, which should drive companies to engage in ecological initiatives and pursue circular models. These models aim to eliminate waste by designing garments with recycled materials, reducing the use of natural resources, and preventing products from being sent to landfills.
The collection of garments for recycling is hampered by laborious and costly processes, the difficulty of separating mixed materials, and the lack of end-of-life textile labeling. Recycling options are divided into mechanical and chemical, each with its advantages and disadvantages, but the technological innovation needed to recycle clothes into new garments on a large scale remains an expensive and unachieved goal.
Textile sector’s sustainability: a significant boost from chemistry
About textile sector’s sustainability, good news comes from Denmark, where a group of researchers appears to have found the key that could radically change the scenario.
A research team led by Professor Steffan Kvist Kristensen at the Interdisciplinary Nanoscience Center of Aarhus University in Denmark has developed an innovative technology that seems to overcome the obstacle of separating mixed fabrics. The research, published in Green Chemistry and also featured by the World Economic Forum for its promising implications, aimed to achieve the separation of textile fibers, thus taking a step forward in the efficient recycling of this type of material.
We’re talking about a patented technology: Aarhus University co-owns the patent (number WO2023194469), which covers the process for breaking down elastane, developed as part of a research project for decomposing polyurethane, the main material used in foam for mattresses and sofas. Stefan Kristensen explains:
«We have developed a method to completely remove elastane from nylon. We have not yet fully succeeded with cotton, as some cotton fibers break during the process. However, we believe that, with a few minor adjustments, we can also solve this problem»
What is elastane
Elastane, also known as Lycra or spandex depending on the country, is a synthetic fabric renowned for its exceptional elasticity.
Invented in the 1950s, the origins of elastane trace back to 1937 in Germany, when polyurethane, the polymer from which elastane was later derived, was first developed in the laboratories of Otto Bayer.
During those years, particularly throughout World War II, polyurethane was used for a variety of applications, including aircraft coatings and as a rubber substitute. However, it was not until after the conflict ended that the DuPont Corporation recognized the potential of polyurethane to produce highly elastic fabrics, leading to the creation of elastane.
Over the years, this material has become increasingly widespread, and today elastane is extensively used in a wide range of garments, from form-fitting underwear to sportswear and swimwear, thanks to its ability to provide stretch and conform to the body’s shape. Elastane is also a key component in socks, work garments, and even in motion capture suits used in the film industry: actors wear these suits in front of a green screen, and the clingy characteristics of elastane allow for the sculpting of 3D appearances onto the captured images.
On the flip side, notwithstanding all these positive attributes, concerns arise regarding the environmental impact and carbon footprint of elastane. Since the core components of this fabric are formulated in the lab, the acquisition of raw materials for elastane is not considered an environmentally degrading process. However, the production process of this fabric is energy-intensive and involves the use of a range of toxic chemicals which, if not disposed of properly, can harm the environment.
Most importantly, and this brings us to the purpose of the research, garments made with elastane fabric are not biodegradable.
Textile sector’s sustainability: how to separate elastane from nylon
To understand the challenges involved, one must start with the characteristics of the material itself.
Elastane is an elastic material, composed of long chains of molecules around which other textile fibers, such as nylon or cotton, are intertwined. Once woven together with other fibers, separation becomes difficult. The research team at Aarhus University explains how the molecular chains of elastane are held together by a small molecule called diamine.
«The method we have developed to separate elastane from other fibers – explains Steffan Kvist Kristensen – requires heating the fabrics to 225 degrees Celsius and adding alcohol and a base of potassium hydroxide. Potassium hydroxide is one of the main components of standard drain cleaners. We found that adding it accelerates the process and effectively increases the speed of the chemical reaction».
This process breaks the chemical bonds of elastane, causing the disintegration of its long molecular chains and thus allowing the separation of materials. The entire process, Kristensen further explains, takes place in a sort of large pressure cooker, where the fabrics are placed together with the alcohol and potassium hydroxide, and then heated.
After about four hours of “cooking,” the materials are separated, significantly facilitating the recycling of fabrics that would otherwise be difficult to dispose of in an eco-friendly manner, avoiding the use of harsh chemicals.
In presenting the results obtained by the workgroup, Kristensen also emphasizes that so far, this technology has been tested on a small scale, using a minimal amount of fabric at a time: essentially, a pair of socks. Nonetheless, this technology is replicable on an industrial scale.
It is no coincidence that the Danish team is eyeing nearby Germany, with its solid tradition of chemical companies that could implement it on a larger scale, thereby paving the way for the recycling of large quantities of fibers from garments containing elastane, thus promoting greater sustainability in the textile sector.
A boost from proteins
A similar field of research is being pursued by a team from MIT, led by Ariel Furst. The Furst Laboratory utilises tools from electrochemical, biological, and materials engineering to investigate electron transfer at abiotic-biotic interfaces. The findings from this research are then applied in the development of low-cost, user-friendly technologies for human health, environmental remediation, and sustainability, based on an understanding of biological redox processes.
About textile sector’s sustainability, against microplastic pollution originating from synthetic textiles, Ariel Furst’s team has focused on identifying proteins capable of degrading the polymers present in fabrics.
In this instance, the process leverages selected proteins to literally “dismantle” the textiles. These proteins can attach to non-cotton polymers and degrade them before they release microplastics into the environment. According to laboratory research results, using these proteins, garments can be decomposed in just two weeks.
This methodology also opens the door to the reuse of other materials, such as pesticides and water treatment chemicals, using similar concepts based on the employment of inert microorganisms capable of degrading harmful chemicals.
In the process defined by Furst, artificial intelligence plays a crucial role, essential for modelling and optimising this recycling process. Through the use of complex AI models, it’s possible to efficiently organise waste streams and match them with the most suitable recycling solutions.
Glimpses of Futures
Let us now try to analyze – from a future perspective and according to the criteria represented by the STEPS matrix – the importance of this kind of studies about textile sector’s sustainability.
S – SOCIAL: the social impact of sustainability within the fashion sector is increasingly apparent, driven by a growing consumer awareness of the environmental and social consequences of their purchasing decisions. Consumers play a crucial role in this rising demand for sustainable fashion, which translates into a call for ethical practices throughout the supply chain, including safe working conditions and fair trade practices. Industry stakeholders are beginning to recognise the importance of a widespread commitment to issues of social responsibility, transparency, and sustainability. Initiatives such as upcycling and the circular economy not only reduce textile waste but also make a positive contribution to society and the environment.
T – TECHNOLOGICAL: we have highlighted how chemistry and biotechnologies can assist in addressing one of the most serious problems in the textile and fashion sector: the disposal of mixed fabrics. In fact, within the realm of waste disposal and management, robotics could also provide significant support. Robots capable of recognising and selecting waste based on the material composition are under development. These robots, equipped with advanced cameras and computer vision systems, use artificial intelligence to analyse the visual properties of waste, such as colour, shape, and surface patterns. This information is then processed by software that identifies the type of waste and coordinates a robotic arm to separate the materials.
E – ECONOMIC: the research discussed in this article heralds a significant shift from a linear economy to a circular economy in the fashion sector. This transition is not just an environmental milestone but also a significant economic opportunity. In the linear economy, companies within the sector use raw materials, including synthetic materials, to create products that end their life cycle once discarded by consumers. This model has severe environmental repercussions, such as resource depletion and pollution. The move towards a circular model, as posited two years ago by McKinsey and advocated by the Ellen MacArthur Foundation, encourages the use of sustainable, reusable materials with lower CO2 impact. This transformation not only mitigates environmental impact but also unlocks an economic opportunity worth $560 billion, with the potential to grow to $700 billion by 2030.
P – POLITICAL: while the research community is making strides in solving technical issues, legislators in Europe and the United States are working to define regulations that extend the responsibility of fashion brands to cover impacts across the entire life cycle and supply chain of their products. Particularly through the EU EPR (Extended Producer Responsibility) for Textiles, the aim is to improve the recycling of clothes and waste management, ensuring that brands bear the costs of environmental damage and waste management resulting from their activities. This approach should also ensure fair and just practices throughout the industry, especially towards partners in low-income countries who bear the brunt of poor production conditions and environmental pollution.
S – SUSTAINABILITY: the report titled “Unfit, Unfair, Unfashionable” underscores the fact that from 2000 to the present, consumption of clothing, footwear, and accessories has doubled, while prices have continuously decreased, making fashion more accessible but also more disposable. This phenomenon has led to a reduction in the usage time of garments. The increase in consumption volume, coupled with a decrease in usage time, significantly contributes to the environmental impact of the sector. The European Union alone, according to the European Environment Agency (EEA), produces 12.6 million tonnes of textile waste each year, the majority of which is either burned, exported, or ends up in landfill. Clothing and footwear alone account for 5.2 million tonnes, equating to 12 kg of waste per person per year. Only 22% of this waste is collected separately for reuse or recycling. This is enough to make not only the modification of economic models but also the pursuit of technological solutions aimed at addressing the most critical issues related to materials both interesting and desirable.
