Can fabrics such as polyester be recycled?

How sustainable are organic cotton, recycled polyester and lyocell really?

Whether expensive quality clothing or a T-shirt from the discounter: More and more textiles are made from polyester. There are plenty of alternatives - but how sustainable are they really?

The resilient, durable plastic is a popular material in the textile industry; now more than half of the clothing produced worldwide is made of polyester. But it pollutes the environment - Swiss waters are also affected, as a study by the Swiss Federal Materials Testing and Research Institute shows: with each wash cycle, the garments shed plastic fibers - one kilogram of laundry resulted in 0.1 gram of microplastic. Only 90 percent of this can be filtered out by the sewage treatment plants, the rest ends up in the rivers and lakes.

On the one hand, better filters for washing machines or sewage treatment plants would offer a solution - or a more conscious consumption of polyester clothing and a switch to natural materials. But even cotton - a quarter of our clothing is made of it - does not have a good reputation: a large amount of water, pesticides and fertilizer is required for cultivation.

Organic cotton, recycled polyester or Lyocell - more and more environmentally friendly alternatives to plastics and conventional cotton are available on the market. But what about their sustainability?

Recycled polyester is trendy

Labels such as Adidas or Patagonia are sure of the innovative alternative: existing polyester is melted down and processed into new fibers. «Recycling definitely makes sense. The amount of polyester that ends up in landfills or, even worse, in the oceans is reduced - as is the consumption of crude oil that is not always available for new polyester », says Prof. Dr. Birgitt Borkopp-Restle, Head of the History of Textile Arts Department at the University of Bern. Less energy consumption and less CO2-Emissions from production also speak in favor of the recycled material.

The problem of bleaching

However, one difficulty in recycling the plastic is that the resulting polyester is not a pure white color; the bleaching process is associated with a high consumption of water and chemicals. And this is necessary in order to create a starting point for good staining results. In addition, polyester cannot be dyed with biodegradable dyes, but only with the use of strong and potentially toxic chemicals.

Another big challenge for sustainable brands like the American retailer Everlane is the lack of elasticity, because there is still no really recycled elastane. The biggest problem, however, remains the release of synthetic fibers: It doesn't matter whether a piece of clothing is made of new or recycled polyester. A 2016 study by the University of California at Santa Barbara found that older fabrics release even more particles into the environment than fresh polyester.

Lyocell and viscose - not exactly the same

Tear-proof, resilient, absorbent and particularly soft: With these properties, lyocell and viscose are becoming increasingly popular. Not only with that, because the fabrics are made from 100 percent wood, more precisely from the cellulose, especially from beech wood, globally from eucalyptus or bamboo and are therefore plant fibers.

However, there are differences between these textiles in terms of environmental compatibility: While the viscose and, more rarely, rayon processes require a lot of energy and water, the more recent production of lyocell is convincing with its significantly lower consumption and, provided it is not processed with harmful agents, classified as environmentally friendly.

"As a further development of viscose, lyocell is an interesting product," says Borkopp. With the advent of lyocell, both the high water consumption and shelf life can be significantly improved. "

Compostable thanks to Lyocell

The producers have also come to the advantages of lyocell: The Swiss lingerie manufacturer Calida, for example, advertises its “I Love Nature” line, a “100 percent biodegradable natural product made from lyocell and thus compostable”. It takes six months for a piece of clothing to completely dissolve in the company's own compost, promises Calida. This principle is awarded the “Cradle to Cradle” certificate - a consumer good is designed in such a way that the raw material it contains can be taken up again and again in the biological cycle

However, even with this material, one must think one step further: If the textile industry is to supply a global market, the question arises from which trees the wood fibers for lyocell can be obtained from in the future. “Beech trees grow much more slowly than spruce trees, for example - and climate change is also affecting forests. Forestry has to come up with new concepts in order to maintain healthy, resilient and long-lasting forests in the long term, ”the textile expert points out.

Is organic cotton the solution?

More and more large fast fashion suppliers such as Zara or H&M are relying on cotton from the “Better Cotton Initiative” to underline their commitment to more environmentally friendly materials. But even if this cultivation is more sustainable than conventional cotton, from an ecological point of view it cannot be compared with organic quality - only a reduced amount of pesticides is needed to produce BCI-certified cotton, and genetic engineering is not prohibited. Even so, the garment is marketed as ecological.

When growing organic cotton, on the other hand, no pesticides are used at all, and a 91 percent lower water consumption compared to normal cotton is one of the main arguments of the organic variant. But the cultivation of organic cotton needs much more area for the same yield, which is why it would be difficult for the producers if suddenly all manufacturers switched to the more sustainable variant of the plant: “Farmers with smaller areas and fewer employees are at a disadvantage as long as they do cannot charge significantly higher prices for organic cotton, ”said Borkopp.

Conversion to organic farming

But only one percent of the cotton planted is organic. As early as 2014, various clothing manufacturers complained that the demand for organic cotton had overtaken the supply.

The process of converting from conventional to organic farming takes a good three years. For this, however, the farmers not only needed financial support, but also training: For example, the German fashion label Armedangels founded the Armedangels Organic Farm Association to help 366 small farms in India with the conversion - even though they don't yet own the company supply with certified organic raw materials.

The solution begins on a small scale

With every more sustainable alternative, you have to weigh the benefits and disadvantages and make compromises: "The production of organic cotton, Lyocell or recycled polyester is certainly an important and trend-setting step," says Borkopp. Because here, as for many other goods, the following applies: The main ecological problem of the fashion industry lies in overproduction - too many clothes are made that are sold too cheaply, washed too often and worn too short. Against this, more and more approaches are being found; For example, the American outdoor clothing manufacturer Patagonia offers a repair service for damaged clothing with Worn Wear.

But if the end consumer is not prepared to buy a high-quality shirt and wear it longer than three cheap shirts, then sustainability and environmental protection will not get anywhere. The most sustainable garment in the wardrobe is not always the one made from an environmentally friendly fabric - it is the favorite item that will be worn throughout life.