Fibres of the future – How is science combating fashion’s sustainability problem?

AMSilk is the world’s first industrial supplier of vegan “spider” silk. The German start-up uses a patented biotechnology to create a smart, silk-like formulation that can be used to replicate that luxury silk-like quality in clothing. 

“AMSilk’s unique bio-fabrication process uses the blueprint for silk from the genome of a spider and reprograms the microorganisms to enable them to produce silk polymers”.

In other words, by studying the unique DNA coding in spiders themselves, scientists can copy their super strong silk-making strategies, using bacteria and natural fermentation processes to produce a similar material at scale. 

“The microbes are grown in large stainless-steel vessels, fed with natural and renewable plant-based raw materials. This creates ‘vegan silk’ which does not involve any natural farming processes,” Scherbel says.

AMSilk fibres are designed with the product’s end of life in mind: they are 100 percent biodegradable, taking just a few months to break down in seawater and on land. As well as yarns, AMSilk’s “biosteel” product can be developed for sprayable formulas, hydrogels and powder for use in a number of applications including textiles, medical devices and consumer goods.

2. Biofibre: Turning food waste into fashion

One of the most promising areas of research into the future of fashion comes from existing agricultural waste. The ability to replace fossil-based fibres with natural, renewable ones is already a positive step forward, but to create them out of food crops that would ordinarily be left to rot in a field? Even better.

Agraloop, a textile innovations arm from US-based start-up Circular Systems, is working to turn this idea into a mainstream reality using the left-overs from food and medicine crops, including pineapples, bananas, oilseed and CBD hemp. Using a special wet processing technique, they extract the cellulose fibres from plant stems and leaves, which are then purified into “soft fibre” bundles, ready to spin into fabric yarn.

According to the company their process uses 100 per cent less water than traditional cotton manufacturing and 53 per cent less CO2 than traditional hemp. The result is a versatile product that can be seamlessly swapped in for traditional fossil-based fibres such as polyethylene terephthalate (PET).

Circular Systems is already working with major international clothing manufacturers for brands including H&M and &OtherStories, all of which benefit from this easy transition, as Andrew Schulenburg, senior vice president of marketing explains:

“We’re really focusing on keeping the natural fibre in tack, so looking at ways to refine the cellulose into a staple fibre that is practical, but which also works aesthetically.”

An important part of the Agraloop process is about creating a fair system for the farmers who supply the crops, too.

The company is investing in “multi-purpose cropping” – that is, finding ways to create higher value from the residue of existing food and medicine crops rather than creating demand for new crops, and therefore limiting the physical and carbon footprint of farming.

“It’s really important that we work with farmers who are ethically aligned with our mission,” says Schulenburg.

“The challenge is also about scale: how to get enough plant residue to allow us to produce enough fibre at a price that is palatable for the industry and fair to farmers too.

3. Wood-based glycols: Cutting out oil from textiles

Glycols have long been a cornerstone of the chemical industry, and especially when it comes to generating the softness and flexibility we have come to expect in our clothes. But traditional glycols have a dirty secret: they are derived from fossil resources, predominantly crude oil and coal.

One day soon clothing manufacturers will have no excuse but to say goodbye to fossil-based glycols for good. Next generation biochemicals to replace fossil-based components in polyester will be manufactured at UPM’s Leuna biorefinery soon.

Not only is the renewable glycol derived purely from locally-sourced beech trees, the process boasts optimised CO2 emissions and provides a seamless replacement for manufacturers.

Laboratory manager (R&D) for UPM Biochemicals, Sebastian Funtan oversees the development of new applications for sugars and glycols derived from wood at the Leuna biorefinery in Germany.

For the textiles industry, change is often quite slow, he says.

“Changing to new products means brands and manufacturers have to do research and work to see how they can adapt their processes to retain product quality. It's a unique selling point therefore for them to be able to just switch directly from fossil-based glycols to the bio-based ones without having to change anything in their processing.”

As of this year, the biorefinery enables the mass production of biochemicals including renewable glycols for the first time.

It’s early days for the refinery, but Funtan hopes the research taking place there will one day soon expand to develop other uses for glycols, too:

“There is a lot of interest in this from manufacturers who all want to make their brands more sustainable.”

The biggest challenge is meeting demand: Leuna refinery will produce 220,000 tons of product including glycols each year. According to Funtan, the global demand for this type of glycols is currently at 35 million tons per year – that’s the same weight as 163,487 commercial aircrafts.

“The good news is the beechwood we use is a renewable resource, unlike fossil-based oil. We can only be one part of the solution, but I am hopeful for the future of sustainable textiles.”

Why recycling textiles alone is not the answer?

One of the biggest challenges in making clothing more sustainable, is that textiles are not easy to recycle fully. We can swap and share items, sell and buy second-hand, but to break down the fibres of the fabrics themselves to fully recycle their parts? It’s a challenge.

Globally, it’s estimated that just 12 per cent of the material used for clothing ends up being recycled. The biggest reason for this is that clothes are often made from a complex combination of fibres, dyes and fixtures: they are rarely homogeneous in their components. Even that favourite cotton shirt is likely to contain some elastane, plastic buttons and a polyester label.

According to Laboratory manager (R&D) for UPM Biochemicals, Sebastian Funtan one of the biggest problems comes with polyethylene terephthalate (PET), which is one of the main polymers for synthetic fibres of textiles and clothing.

“We see a lot of companies selling clothing where they specify that a certain amount of it is from recycled PET. Unfortunately that PET is mostly derived from bottle waste, which means they are not solving the textile PET problem.”

And there’s another major reason why recycling alone is only a finite solution:

“Recycling always means that you lose some properties of the item. For example with PET the molecular weight gets lower and at some point it cannot be reused anymore.”

Looking to the future, manufacturers should think about two things, Funtan says: the properties of the synthetic fibre but also the role it has to fill – the longevity of the product.

"The brands should also design new textiles with End of Life in mind. Of course, usage and recycling of the product as much as possible is very important. But once unusable, the product should not be deposited on landfills or incinerated since this is removing the carbon from the loop."

Equally, consumer understanding of where products come from, and the limitations of recycling has a key role to play, he concludes.