Swiss Empa – Clothes recycling – “Consumers should ask critical questions”

Switzerland and the EU are pushing the reuse of raw materials. But despite the best efforts, the circular economy in the textile industry sometimes produces abstruse blossoms. After all, recycling can also harm the environment. Empa researcher Claudia Som dispels sustainability myths in an interview and tells consumers how to recognise black sheep.

By guest author Norbert  Raabe from Swiss Empa

Ms. Som, together with your colleagues at Empa, you investigated the environmental impact of an outdoor jacket made of recycled material. One of the results was that the use of polyester from PET bottles does not yield any advantage – perhaps surprisingly for laypeople. Did you expect that?

Even before our study, we had heard from experts in the packaging industry that “bottle PET” would be better left in the bottle cycle for quality reasons. There were even rumors that resourceful entrepreneurs abroad were producing PET bottles not for beverages, but to profit from the high demand for “recycled PET.” Therefore, it is necessary to look closely at where the PET comes from and what quality requirement it must meet for a number of recycling loops – especially if many of those are to be achieved.

Recycling and circular economy in the textile sector has long been an issue in politics as well. You recently conducted a survey among Swiss textile companies to explore the potential. What were your findings?

The idea to take a closer look at production waste in the textile industry came to us during a company visit. Although the company tried to reduce waste and find a sensible reuse, a large part of high-value materials ended up being incinerated. Often, companies also remain in the dark about what buyers do with the material. What was interesting for us was that designers can also help to avoid production waste – for example, by tolerating colour deviations.

Today, most clothing ends up in incineration or landfills at the end of its life. How high do you estimate the potential for recycling?

From our contacts with Swiss and European industry, we have learned that successful recycling depends on how well you know the composition and quality of your materials. Moreover, large enough quantities are required for the processes to become economical. Today’s clothes that are sometimes made of really wild material mixtures and our “fast fashion” approach with low material quality make successful recycling quite tricky. Thus, we hope that our research on Swiss production waste will contribute to establishing a circular economy faster. After all, in Swiss as well as in European production, the quality of the materials is relatively high, the composition is largely known, and relatively large quantities of the same material are produced.

Does recycling make sense in every case?

Recycling is not always sustainable. On the one hand, the effort required for recycling can be high – if only because of the logistics. On the other hand, problems can arise from material and quality losses or from impurities in every recycling process. The EU and Switzerland want to strongly push recycling. However, this could lead to even greater environmental problems – for example, if the recycling technology requires a lot of resources.

There are now numerous initiatives from manufacturers, such as labels for sustainable products or recycling – this can be quite confusing for customers. Do you have any tips for consumers to find their way around?

Even experts have trouble keeping track of the topic. I recommend the label guides from non-governmental organizations. Consumers should also ask critical questions, such as where the PET comes from, where it is produced. That way, you at least get an idea of how much the suppliers know and how committed they are.

In the Subitex research initiative (see info box) Empa researchers are working together with the textile industry in an interdisciplinary way. What are the most frequent questions companies come to you with?

Substitutes made from bio-based materials are a big topic: Are they really better than fossil-based ones? Are synthetic textiles a problem for the environment because of microplastics? Does it make sense to rely on compostable materials, or is the longevity of the product perhaps more important? Questions like these motivate us to establish a sound basis for an informed decision-making in the industry.

The Swiss textile industry is increasingly focusing on innovative solutions, including novel materials, one of Empa’s main research topics. For instance, you compared conventional polyester with bio-based polyester. Which materials do you see as the hope for the future?

Wood-based materials are exciting. A material that can bind COdirectly from ambient air, like innovative concrete, would also be interesting – in other words, textiles as a store for greenhouse gases. But that’s perhaps a bit too futuristic (laughs).

Literature
T Ivanović, R Hischier, C Som; Bio-Based Polyester Fiber Substitutes: From GWP to a More Comprehensive
Environmental Analysis; Appl Sci (2021); doi: 10.3390/app11072993

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