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22 February 2017

Researcher portrait: Åsa Östlund gives textiles new life

A sock with a big-toe-sized hole is not worthless. The fibres can become new clothes, at least in theory. In practice it is problematic. Åsa Östlund at Mistra Future Fashion wants to change this. But for recovery and recycling to be workable, changes are required at every stage.

‘Never again!’

Åsa Östlund had completely made up her mind by the time she left the Gruvön paper and pulp mill in Grums, Värmland, after working there every summer from the age of 17 until she left university.

‘I was employed at the lab and took lots of routine samples, but I never understood why. My colleagues were good, but the routine work was so tedious that I promised myself I’d never work on cellulose again.’

Things turned out differently — but more about that below.

Today, Åsa Östlund is the Deputy Programme Director at Mistra Future Fashion. She is one of the people trying to develop methods that will make it easier and more efficient to transform worn textiles into new ones. One place where this is being done is KTH Royal Institute of Technology, here in Stockholm; another is Gothenburg.

The reason why she and the research programme are taking such pains to do something as laborious as breaking down intractable molecules and then putting them together again is that consumption of textile materials is increasing at the same rate as Earth’s population. This effect is reinforced by the fact that a rising number of people can afford to buy clothes. The trend is not sustainable in the long term, either for the environment or for resources.

In Sweden we buy an average of 13 kg of clothing per person annually. Of this total, 8 kg finally ends up in waste, while 3 kg is reused in one way or another. If we were to use our clothes three times longer, their environmental impact would decrease by 70%. Although the exact figures vary around the world, the trend is similar in most countries.

‘That’s why we must both increase recycling, recover and reuse of textile materials,’ Östlund says.

New methods wanted

Today, only small quantities of discarded textiles get a new life. This is explained by several factors, but one is simple: there are few methods of making use of the fibres that fabrics contain, at least if such methods must also be financially and environmentally acceptable.

Åsa Östlund trained as a physical chemist and, in her endeavour to get away from the pulp mill, chose as her next job one in the pharmaceutical industry. There, she worked mainly on molecules that do not readily dissolve, their dissolution and their interactions with proteins.

‘After I’d worked there for a while a doctoral position at Chalmers University of Technology came up. The crux was that I’d study water interactions — in cellulose… But suddenly the subject interested me.’

She was still a long way from the fashion industry. But when Mistra Future Fashion was about to start in 2011, Östlund was asked whether she would like to become the Deputy Programme Director.

‘I had no knowledge of the sector, but I was attracted by the prospect of joining in the creation of sustainable fashion. My knowledge proved valuable when we started to ponder how a recycling system for textiles might work.’

Mistra Future Fashion was initially organised around eight projects in which each discipline was a part in its own right. In each of these areas, great progress was made; but bringing about cross-boundary work was trickier. The scientists preferred to stay within their own narrow specialities, which made it difficult for them to understand one another.

‘At first, I sometimes tried to get researchers from different disciplines to study a problem together, but they often came back with a solution each. I didn’t think it would be so difficult to get collaboration up and running.’

Mixed materials an extra challenge

It took Åsa and the other programme management members two years to get the interdisciplinary research started. But now they have embarked on a second programme it is working, she thinks. The eight subsidiary areas have also merged to form four: design, supplier chain, users, and recycling and recovery. In addition, small ‘pop-up’ projects are generated as needs arise.

One of these is Re:mix. Under Åsa’s leadership, its purpose is to try and develop methods of separating two textile fibres, nylon and elastane, from other textile materials. The background is the trend in the textile industry towards greater use of mixed materials.

‘This can yield textiles with new properties, but at the same time is makes recycling and recovery considerably more complicated. I used to believe we must ban mixed materials, but since the trend is in the opposite direction we’ve realised the need for methods of separating different types of fibre from one another without destroying them,’ Åsa thinks.

She points out the NMR (nuclear magnetic resonance) spectrometer. This is her primary tool when she wants to investigate, at molecular level, how (for example) cellulose interacts with different solutions or surrounding molecules.

In cooperation with both Swedish and Austrian researchers, she is now attempting to design an enzyme that can cut up polymers in such a way that they can be reassembled. If this is successful it will be possible to take a pair of stretch jeans containing both nylon and elastane, put them into a process and end up with the two materials out in separate heaps. In present-day attempts to recycle jeans of this type, it is possible to recover only one of the two, while the other is sacrificed.

‘It’s not enough to develop a green solution. If it’s going to have a major impact it has to be cheap as well. Today, few manufacturers are willing to incur higher extra costs of recovering and recycling fibres. We’ve also got to ensure that the whole chain from producers to users works properly, if recycling is to become truly important.’

Cotton can rise again in a new form

The textile fibre that is easiest to recover is polyester. But not even polyester recovery and recycling takes place on any substantial scale. There are also some questions about whether the present technique is reasonable in cost or environmental terms.

‘If it’s going to be interesting, the amounts of energy and chemicals used in the recovery process must be reduced. Another option is to recover polyester from other sectors; PET bottles, for example, can be turned into textile fibre. These bottles have the advantage that, when they are so worn as to be no longer usable for beverages, they have a molecular weight that is perfectly suited to textile fibres.’

The most common textile fibre is cotton, but it is a fairly awkward material. One reason is that its production is far from environment-friendly. Another is that recovering and recycling it are difficult. A third problem is that cotton becomes very worn during use and washing. New garments can therefore contain only a maximum of 20% recycled fibre. The remainder has to be virgin raw material.

‘On the other hand, if we take the worn cotton fibres and make viscose, we get a considerably higher recycling rate,’ says Åsa, showing the blouse she is wearing today.

It is made of Lyocell, a cellulose-based textile material with a marked silkiness that, just like viscose, can be produced from recycled cotton fibres. It is a clear example of how tomorrow’s clothes can be both green and attractive.

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