What about the empty bottle?

Producing textile yarns out of PET bottles

In Guben, the company Trevira produces textile yarns from recycled polyethylene terephthalate (PET), and they do not differ from newly produced yarns in terms of their appearance and quality.

The rain jacket is bright red, waterproof and windproof and it looks as if it could withstand a winter’s day at the Baltic Sea. Tim Biemelt works for Trevira’s development department and presents the jacket in the production hall in Guben. However, this presentation is not about the latest collection of functional apparel, but about the yarn from which the jacket was made: Trevira produces it entirely out of recycled PET bottles.

“As a scientist, but also as a consumer, I have long wondered how we could use our planet’s resources more prudently,” says Biemelt, “It makes sense to plan and optimise products in a way that integrates them into a closed-loop economy.”

At Trevira, Biemelt starts his work at the end of the first life cycle of the PET bottles. These bottles are turned into their original granulate materials at the parent company Indorama. They have been delivered to Trevira at a consistently high quality for years. “The label on most commercially available bottles is usually not made of polyethylene, and neither is the lid. These parts must therefore be removed prior to the recycling process,” says Biemelt. The bottles are also sorted by colour in order to obtain granulate materials that are as uniform as possible and only slightly discoloured.

During the spinning process in Guben these granulate materials are squeezed at a very high pressure through a nozzle from which a multifilament emerges. This multifilament can, in turn, be dyed directly during the spin with the help of various additives. “This processing ultimately provides me with a yarn that has the very same textile properties as a yarn made from fresh polyester,” explains Biemelt. After the spinning process the yarn is then given the desired texture so that it can be used for weaving or knitting.

In recent years the price of the reprocessed yarn has come very close to that of newly produced yarn. There is still a small mark-up due to the more complex processing, but this mark-up could be compensated by marketing activities.

In Brandenburg, Trevira sees itself as a pioneer in the production of textile yarns from recycled materials and bio-based plastics. “It is very advantageous for the state of Brandenburg that we are breaking new ground,” says Biemelt. The state also offers numerous advantages, such as networks for innovative companies and research centres, funding programmes and a good infrastructure. “However, we are also tied up in red tape,” says Biemelt, “We could achieve much more in some projects if we could cut the red tape.”

Despite some minor obstacles, he is still optimistic about the future. “It’s not only that there is increasing political pressure with regard to recycling, consumers are also explicitly calling for sustainable products,” says Biemelt. The team in Guben also wishes to make a contribution towards saving natural resources. “Ultimately, we also have a good feeling when we offer our customers a sustainable product,” points out Biemelt.