A milestone in textile-to-textile polyester recycling at scale - Just Style
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A milestone in textile-to-textile polyester recycling at scale

By admin-demo 17 Nov 2020 (Last Updated July 21st, 2021 12:34)

Swedish fast-fashion brand Monki has launched the first capsule clothing collection made using a breakthrough textile-to-textile recycling process. Jenny Fagerlyn, Monki’s global sustainability director, and Erik Bang, innovation lead at H&M Foundation, tell just-style why the technology – which is being scaled up before being made widely available to the apparel industry and its supply chain – is a huge step towards a closed loop for clothing.

“This collection is a milestone beyond just clothing, it is a meaningful milestone for the benefit of the planet, right here and now,” says Erik Bang.

The Monki line-up consists of just two garments – a grey hoodie and track pants – made using the so-called Green Machine technology, but it marks a tipping point on the fashion industry’s path to a circular model.

For it’s the first time a hydrothermal system that can fully separate and recycle cotton and polyester blended fabrics into new fibres has moved from trial to products. 

And it’s about to be scaled up for commercial production at Indonesian manufacturing giant PT Kahatex, before the technology will be made available under license for anyone to use.

Developed through a research collaboration between the non-profit H&M Foundation and HKRITA (The Hong Kong Research Institute of Textiles and Apparel) – which owns the intellectual property (IP) – the process uses a closed loop of just water, heat and biodegradable green chemicals to separate the fibres, which can be used again and again.

It focuses on cotton and polyester blends, the most widely used clothing material but until now impossible to separate and recycle commercially. 

Uniquely, the recovered polyester comes out in fibre form and can be reused directly, without any loss of quality. On top of this, the technology is cost effective, and it tackles the logistical nightmare of moving waste textiles around the world.

It is also environmentally friendly.

“It’s a very benign and elegant process,” Bang explains. “It’s like a pressure boiler that you might have in your kitchen. A combination of heat, water, pressure and citric acid – which is basically lemon juice – separates the fibres and takes the colour out of the fabric.

“The real advantage [with the Green Machine] is that we’re not breaking down the polyester. We’re recovering it in fibre form and with fibre quality, so we can re-spin it into a yarn right away”

“Another very exciting part is that this is textile-to-textile polyester, and not PET bottles to textile. There are no good textile-to-textile polyester recycling solutions, so although we can make a garment from PET bottles we can’t recycle it.

“The real advantage [with the Green Machine] is that we’re not breaking down the polyester. We’re recovering it in fibre form and with fibre quality, so we can re-spin it into a yarn right away.”

This is exactly what will happen at PT Kahatex, the technology’s first industrial collaborator.

One of the largest textile and clothing enterprises in Southeast Asia, the vertically integrated supplier produces everything from polyester fibres, yarn and fabric, to garments and socks.

Not only has it made Monki’s new capsule collection, but it is also due to take delivery of the first Green Machine and will play a key role in helping to optimise the hydrothermal separation process on a larger scale.

“They’re a great industrial partner, they have the technical know-how, and because they specialise in jersey they have a great fit for the type of product that we can make at this stage.”

The system is currently configured to separate about a ton and a half per day of blended fibre materials. And because it’s modular, it’s a simple case of adding more units – either independently or in coordination – to build capacity. 

“So it doesn’t have to be a very heavy investment if you have a small operation, you can still recycle if you buy one or two of these modules. And if you have a big factory you install more modules as you expand.” 

Technical, economic and logistical challenges

The Green Machine is the culmination of research that began four years ago.

With millions of tons of textile waste ending up either discarded in landfills, or downcycled into insulation, carpeting, and other low value applications each year, “there are lots of great initiatives trying to solve closing the loop or recycling of textiles.

“But when we started in 2016 we saw a gap in terms of progress on separation and recycling of the blends: polyester being the most common type of fibre, and blends the most common type of textile in the world. We saw an opportunity to target this at scale,” Bang explains.

“With the Green Machine we can recycle where the waste is. It doesn’t make sense to ship waste back along the supply chain to recycle it on the other side of the planet”

To tackle the technical challenge, the team at HKRITA worked with a group of retired researchers and scientists from Shinshu University in Japan. With ages ranging from 68 to 82 years, and more than 500 years of combined experience in creating new cellulosic and synthetic fibres, “we asked them to reverse the process. And they helped us solve this problem.”

But this was just the first step. There was also the economic challenge of making the process commercially viable.

“Because polyester is so cheap, you need to have a very competitive process to enable recycled polyester to compete with virgin polyester on price. This is why the Green Machine is modular, why we don’t break down the polyester, and why it’s a closed loop system so we recover the heat, water and chemicals.”

In contrast, the current process of using PET plastic bottles as the raw material for recycled polyester is not only costly but requires specialist equipment and “a big, super-expensive factory” to convert the material back to its original monomer feedstocks before it can be reconstructed in fibre form. 

Likewise, other chemical and mechanical recycling processes degrade the fibre so that it needs to be blended with virgin materials for strength, and cannot be recycled over and over again. “This is not part of the solution.”

Bang also points to the logistical challenge of “the stuff we want to recycle sitting with the consumer at the end of life, but we need to get it back to be able to recycle it.”

Game-changing potential

It’s here that he believes the new technology has more game-changing potential.

“I’m very excited that recycling will unlock a number of other levers when it comes to how the fashion industry is set up, its dynamics and its structure.”

The used clothing trade faces numerous challenges, including higher tariffs than new garments, and restrictions imposed by many countries – including China.

“When it comes to recycling, trading with waste is not easy. Waste is a symbolic good that no-one wants to import or take on. But with the Green Machine we can recycle where the waste is. It doesn’t make sense to ship waste back along the supply chain to recycle it on the other side of the planet. 

“So I think we will see regionalised and localised recycling, as well as garment collecting, within trade blocs of the EU, the US and others. And that will enable a whole new set of localised production, on demand, and closer to the customer. 

“This will take away the need for inventory and pre-planning of collections: you can run the cycle much closer to actual demand and that, in itself, will reduce the waste of overproduction and loss in the supply chain.”

No single solution

Both Bang and Fagerlyn emphasise that the Green Machine is just one solution to the bigger goal of a circular fashion system.

“The challenge is that textiles are available in endless variety and composition, so we’re going to need several different recycling solutions working next to each other to be able to close the entire loop,” says Bang.

While the Green Machine recovers polyester from poly-cotton blends in fibre form, the cotton is extracted as a powder that is super-absorbent and can be used in products like diapers.

“We’re still working on the best solution for the cotton, and also researching how to extract animal or protein fibres as a pre-step to the hydrothermal process, so we can recover all the main types of fibres.”

He also points out that there are other – better – technologies to recycle mono-materials like cotton. “You shouldn’t put denim jeans into our hydrothermal machine; that’s a waste of the resource. There’s a better solution tailored to that material.”

Fagerlyn agrees. “What we’re talking about here is one puzzle piece of closing the loop and becoming circular. There are multiple processes and discussions and systems that need to be in place to get the garments back, to get the garments to the right place, should we do that by individual brands or together, and what about post-consumer waste in countries like Indonesia?

“But to get the Green Machine technology out from a laboratory and into a commercial line, that is a huge step.”

Fast-fashion fundamentals

The initial Monki collection uses polyester fibre recovered from cutting room waste, “which is a controlled input since you know the exact composition. As we learn more we will also be able to use post-consumer textile waste.”

Of all the brands in the H&M Group, Monki has “the youngest customer; maybe it’s the first time she’s shopped by herself, she’s very tech driven, lives her life online,” says Fagerlyn. “The challenge with our customer is that they don’t want to wear something more than five times.”

This, of course, is the eternal dilemma facing the fashion industry: How to change the fundamentals of a linear business model based on “making money when we sell more tomorrow than yesterday.”

Bang believes it would be a disaster if progress on recycling was simply seen as a license to “go and consume as much as we have in the past. 

“We still need to talk about consumption, and how to extend product lifetime. What we want to recycle is things at the very end of life, not wearable clothing. So we still need recycling – and we still need to talk about consumption – but those are not mutually exclusive or in contrast to one another. But it’s great that we are at least starting to solve one part of this challenge.”

He also points out that launching the Green Machine with a value fashion brand like Monki sends an important message.

“Sustainability can’t be a premium product, it can’t come with a premium price, it can’t be exclusive, it needs to be inclusive and accessible, and must not be a compromise.”

Circular journey

Fagerlyn also has strong views on wider progress towards a circular economy.

“My belief is that each industry should close their own loop and deal with their own waste into the loop. And I think that is how you build a circular economy in the future – not to try to bend a linear model into a curved one, like using PET bottles for recycled polyester.

“Another important innovation that is also needed is how do you trace a garment to be able to understand what it contains when it comes into a sorting centre or takeback scheme.

“There is a lot of discussion on that, including technical solutions that can load a product with information such as the chemicals it contains, how it has been produced, how it’s supposed to be recycled. As brands it’s our responsibility to invest in platforms and services that ensure the product has a long life.”

Also part of the bigger picture on circularity is designing products and choosing materials, trims and components that can all be recycled, and working with suppliers that are able to take them back. Discussions are also needed on how to prolong the life of a product, and before that, how to produce garments that people want to buy.

“From a brand perspective these are extremely big blocks in our theory of change. Our garments have a very high fashion threshold and we don’t want to compromise on the Monki DNA, just to do it in a different order. It’s a challenge. 

“We live in a climate decade, so to be able to come with solutions and suggestions to challenge the status quo, that’s where you get movement in the organisation.”

The need for change has also been highlighted this year more than ever before. “From trade wars to Covid, it has never been more clear how vulnerable the supply chain is. We need to be much more diversified, Fagerlyn notes.

“Given global developments in general, you don’t want to rely on one single source of production,” agrees Bang. “You need to be a lot more resilient and set up production in different regions closer to the consumer, both to meet consumer demand but also to address environmental concerns, and to address business concerns and risk.

“And if the waste is considered a valuable resource, then the game will change significantly because we have the resource here, we don’t have to grow the cotton somewhere else or extract oil. So that will disrupt lots of things.”