Why clothes are so hard to recycle - iWONDER

  13 July 2020    Read: 1857
  Why clothes are so hard to recycle -   iWONDER

Fast fashion is leading to a mountain of clothing being thrown away each year and has a huge impact on the environment, so can we turn our unwanted garments something useful?

Open your wardrobe and be honest. How long was it since you last wore some of those clothes? Do you think it might be time for a clear out?

Languishing in the back of cupboards and bottom of drawers are outfits that don’t fit any more, items that have gone out of fashion, or even clothes that have never been worn. In fact, according to research conducted by sociologist Sophie Woodward at the University of Manchester, on average 12% of clothes in the wardrobes of women she studied could be considered “inactive”.

If you were brutal, you’ll probably manage to fill a bin-bag or two with clothes you no longer want or need. But what then?

Around 85% of all textiles thrown away in the US – roughly 13 million tonnes in 2017 – are either dumped into landfill or burned. The average American has been estimated to throw away around 37kg of clothes every year. And globally, an estimated 92 million tonnes of textiles waste is created each year and the equivalent to a rubbish truck full of clothes ends up on landfill sites every second. By 2030, we are expected as a whole to be discarding more than 134 million tonnes of textiles a year.

“The current fashion system uses high volumes of non-renewable resources, including petroleum, extracted to produce clothes that are often used only for a short period of time, after which the materials are largely lost to landfill or incineration,” says Chetna Prajapati, who studies ways of making sustainable textiles at Loughborough University in the UK.

“This system puts pressure on valuable resources such as water, pollutes the environment and degrades ecosystems in addition to creating societal impacts on a global scale.”

There are good reasons to seek out alternatives to chucking clothes in the bin – globally the fashion industry is responsible for 10% of all greenhouse gas emissions, with textile production alone is estimated to release 1.2 billion tonnes of greenhouse gases into the atmosphere every year. Vast amounts of water are also needed to produce the clothes we wear too and the fashion industry is responsible for 20% of global waste water. (Read more about the impact our fashion addiction has on the planet.)

At the same time we are buying more clothes than ever – the average consumer now buys 60% more clothing than they did 15 years ago. More than two tonnes of clothing are bought each minute in the UK, more than any other country in Europe. Globally, around 56 million tonnes of clothing are bought each year, and this is expected to rise to 93 million tonnes by 2030 and 160 million tonnes by 2050.

While most clothes with care will last many years, changing fashions mean their lifespan is artificially shortened by consumers changing tastes. Industry figures suggest modern clothing will have a lifespan of between 2-10 years – with underwear and t-shirts lasting just one to two years, while suits and coats last for around four to six years.

Would recycling our clothes help to reduce the toll our fashion addiction has on the environment?  

Currently just 13.6% of clothes and shoes thrown away in the US end up being recycled – while the average American throws away 37kg of clothes every year. Globally just 12% of the material used for clothing ends up being recycled. Compare that to paper, glass and plastic PET bottles – which have recycling rates of 66%, 27% and 29% respectively in the US – and it is clear clothing lags behind.

Indeed, most of the recycled polyester being used now by leading fashion brands in fact comes from bottles rather than old clothing.

Much of the problem comes down to what our clothes are made from. The fabrics we drape over our bodies are complex combinations of fibres, fixtures and accessories. They are made from problematic blends of natural yarns, mand-made filaments, plastics and metals.

“For example, a 100% cotton t-shirt contains many other components such as labels and sewing threads which are usually made from another material like polyester,” says Prajapati. “Similarly, a typical pair of jeans are made from cotton yarn which is generally blended with elastane, and other components such as zips and buttons and polyester sewing thread and dyed using a range of dyes.”

This makes them hard to separate so they can be effectively recycled. Sorting textiles into different fibres and material types by hand is labour intensive, slow and requires a skilled workforce. Growing use of modern fabric blends in clothing also makes it hard to do this mechanically too, although European researchers have been developing techniques that make use of hyperspectral cameras – which can see light beyond the limits of human vision – to better identify different fabric types. Once sorted, the dyes that have been applied to the fabrics need to be removed in order for yarns to be reused.

Currently, however, very few of the clothes that are sent to be recycled are actually turned into new clothing – a process known as “material to material” recycling. Old wool jumpers, for example, can be turned into carpets, cashmere can be recycled into suits. But as of 2015, less than 1% of used clothing was recycled in this way.

While of course there is a healthy market in second-hand clothes being sold online, perhaps the most popular way of disposing of old clothes is simply to give them away so they can be reused through charity shops. Increasingly, however, clothes donations are being used as a way of simply passing on the textile waste problem to others.

At Oxfam’s Wastesaver clothes sorting and recycling plant in Batley, Yorkshire, UK, 80 tonnes of old clothes pass through the factory every week. Lorraine Needham Reid, Oxfam’s Wastesaver manager, has worked at the plant for over 10 years. Over that time, however, she has seen a real decline in the quality of clothes that are reaching them, particularly when it comes to the materials used to make the clothes.

These days, most of what reaches Wastesaver will end up never being worn again. Over a third – 35% of the clothes – go to Oxfam’s partners in Senegal to be sold. Between 1-3% go back into Oxfam shops around the UK to be re-sold.

The majority is sent for recycling in some way, but about six tonnes of the garments are of such poor quality they are simply torn up so they can be used as industrial cleaning clothes and stuffing for mattresses or car seats.

Fibre recycling technologies do exist, but they are only used on a small scale. Generally, the techniques can be separated into mechanical and chemical recycling.

“Blends are most suitable for mechanical fibre recycling, where fabrics are shredded and pulled to transform them into fibres of shorter length,” says Prajapati. Shorter fibre length produces fabrics of lower quality and strength, so the results from this kind of recycling can’t be used for clothing. Instead these tend to then be “downcycled” to produce other composite fibre materials such as thermal insulation or carpet for use in the building industry. Some researchers have found ways of creating noise insulation from old textile fibres.

Chemical fibre recycling for fabrics with large quantities of one type of fibre, for example polyester and nylon are well established, says Prajapati. “However, they consist of multiple processes and additional chemicals, making the process and resulting yarn or fabric costly,” she says.

There has been success on a smaller scale to effectively separate natural and synthetic blends and capture both types of fibres, without losing either fibre in the process. However, scaling up this technology to an industrial scale remains the challenge.

One group of researchers led by Carol Lin, a chemical engineer at the City University of Hong Kong, has developed a technique for recycling fabrics made from cotton and polyester blends by feeding them to fungi. The fungi Aspergillus niger – which typically forms a black mould on grapes – produces an enzyme that can break down the cotton into glucose that can then be used turned into syrup. The remaining pure polyester fibres can then be reused to make new clothing, they claim. Poly-cotton blends are now among the most popular fabrics for use in cheap clothing, commonly used in t-shirts, shirts and even jeans.

Lin and her team have since refined the process so it can be done on a larger scale using industrially produced cellulose enzymes, and have been working with the clothing retailer H&M to examine what impact this recycling process might have on its textile waste.

Austrian researchers have also developed techniques using enzymes that allow them to turn old wool clothing into a material that can be used as a resin or adhesive.

But if we ever hope to make our clothing sustainable, more fundamental changes to the clothing industry will need to be made. Fabrics, fibres and garments will need to be designed in ways that make them easier to recover and recycle.

Some are even looking at turning other types of waste – such as off milk – into clothing
“Recycling needs to be incorporated into the current system to make it more circular,” says Prajapati. “Therefore, the way we design clothes needs to change, it needs to facilitate recycling.”

One option is to create new types of materials altogether, from different sources, that either won’t have the same impact on the environment or might be easier to recycle. Some are even looking at turning other types of waste – such as off milk – into clothing.

When milk turns sour, it separates into whey at the bottom and protein flakes on top. When you remove the whey, you are left with a kind of cottage cheese.

“This cottage cheese is put into a machine that works like a noodle machine,” says Anke Domaske, founder of QMilk, a company that has been developing new types of biodegradable fibres in Hemmingen, Germany. “Together with water you create a dough. At the end there is a spinneret with holes so fine that you do not end up with noodles, but fine fibres that are thinner than hair.”

The company then spins these fibres into yarns, which it says have a silk-like texture. These can then be used to make jersey or woven fabrics, or other textiles like felt. Crucially, when a garment made completely from QMilk fibres is no longer wanted, it can simply be composted at home, Domaske says.

QMilk isn’t the only company creating textiles from unusual sources.

After working for years at a design company in Germany, Renana Krebs saw behind the scenes how poor the textiles and clothing industry is for the environment. She vowed to do something about it and in 2016, she started Algalife, making fibres and dyes from algae.

Algae is already widely used in the beauty industry, in certain foods and it is used to make biofuels. “After learning about all those industries, and the benefits that we get from algae, we asked ‘why not to do this for textiles?’” says Krebs.

One benefit is the algae are harvested in a closed system, meaning there is no freshwater used in the process at all. All the algae need to grow is water and sunlight. By extracting natural colourings from different types of algae, Krebs and her team have been able to combine these with enzymes and fixative agents – which help to bind the pigment to a fabric – from synthetic and natural sources, including oak galls, pomegranate rind and juniper needles.

They have also been able to produce fibres that can turned into yarns by purifying proteins from the algae or even using them to produce a bio-oil that can be turned into bioplastic fibres.

Prajapati has also been working with colleagues at De Montfort University to produce enzymes that could potentially make the clothes dying process more sustainable.

Currently most textiles are coloured using synthetic dyes, which are petroleum derivatives, and patterned with complex processes. These processes can require temperatures of up to 100C for cotton, nylon and wool, but higher for polyester and other synthetic fibres. On top of this, the process requires high pressures, long processing times and the use of additional chemicals such as acids and alkalis, which are harmful towards the environment in large quantities.

Prajapati and her colleagues have been developing processes that use enzymes so that textile dyes and patterning of fabrics can be done temperatures as low as 50C, at atmospheric pressure and pH conditions around neutral without the use of additional chemicals.

“The key advantages over conventional methods include simpler processing of textiles, the elimination of pre-manufactured dyes and opportunities for multiple colours to be achieved through simple alteration of processing conditions,” she says.

Pigments made by Algalife have similar benefits, plus the added benefit of being created from renewable sources, says Krebs. You can even drink the dye they produce, she says. Algalife is now working with a major retail fashion brand and hope to have clothes made from algae in stores by 2021.

Other major brands across the fashion industry are starting to pay attention to the demand for more sustainable practices. Companies like Adidas, that recently announced a range of trainers made from ocean plastic. High street retailer Zara also announced in 2019 that it would be using only sustainable materials by 2025.

“Using recycled, rather than virgin, materials offers an opportunity to drastically reduce non-renewable resource inputs and the negative impacts of the industry, like CO2 emissions, water and chemical use,” says Prajapati.

But some are sceptical about how committed some large brands are to sustainability, accusing them of “greenwashing”, which the companies deny.  

Zara was one of the original inventors of the fast fashion system as we know it, says Clare Press, Australian Vogue’s sustainability editor-at-large and author of the book Wardrobe Crisis. “Let’s not pretend people shop at Zara for heirlooms to pass down through the generations,” she says. “In the last 20 years the fashion system has changed completely, moving away from seasonal drops towards near-instant gratification. Waiting six months for a runway look seems crazy to a new generation of fashion fans raised on Instagram and ‘see now, buy now’.”

So while recycling and more sustainable fabrics will be a key part of the solution, consumers too will need to change their behaviour if we hope to lessen the impact that the fashion industry is having on our planet.

“We need to slow down, take a little time to reconnect with our clothes and appreciate them again,” says Press. “Remember that whatever you are wearing, it took both physical and creative resources to make it.”

By Abigail Beall, 

BBC


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