Things you need to know about Polyester

When we talk about the synthetic fiber polyester, we mean all textiles and fabrics made of polyester yarn. This can be fleece or neoprene, for example. Or also many textiles with a high stretch content, such as running tights or swimwear, and also, for example, softshell jackets and all kinds of athleisure wear. Most synthetic fibers are made of polyethylene terephthalate - PET for short - or polycarbonate, but numerous other plastics also provide the basis for polyester.

Polyester fibers are three times finer than silk and can be woven very tightly into super small-pored fabrics that are windproof and waterproof. The fabric remains breathable and is also very light, heat-resistant and wrinkle-resistant. This is particularly interesting for technical textiles, for example in the outdoor sector: from waterproof hiking clothing to textile travel equipment that needs to be stowed compactly and easily, to backpacks, insulated mats or hammocks and, last but not least, the tent.

Another great advantage of the synthetic fiber is that it can be easily modified. Thus, polyester fabric is often enriched with UV protection or additionally impregnated to make it even more weather resistant.

The uncomplicated fiber can be superbly combined with other textile fibers and is therefore often found in blended fabrics, for example with cotton or viscose. The polyester content provides the fabric with greater dimensional stability and ensures that the garment is easier to care for, wrinkle-resistant or stretchy.

Compared to natural fibers, sports and outdoor clothing made of polyester develops unpleasant odors more quickly. This is because the smooth fibers hardly absorb any moisture, but merely absorb it: Sweat is automatically wicked to the outside. This ensures a pleasant wearing sensation for a while, because no stagnant moisture forms and the textile never feels damp. The skin, however, does, at least during heavy sweating. Polyester fibers lack the natural protective film which, in the case of absorbent natural fibers such as wool or cotton, ensures that no unpleasant perspiration odor spreads for a very long time. Thanks to it, natural fibers have the ability to clean themselves virtually by themselves. Polyester cannot do this and therefore has to go into the washing machine much more often.

That in itself is a major problem: microplastics dissolve from the polyester fabric in the washing machine and end up in the environment via wastewater. The synthetic fiber is so robust that it can hardly be degraded. And there are also downsides to the production process. Although less water is needed than in the production of cotton, the energy input is much higher. Polyester is made from crude oil and is found not only in textiles, but also in PET bottles, plastic-containing products and packaging. 100 million barrels of crude oil are consumed annually for this purpose. The textile industry accounts for 70 percent.

To conserve resources, many textile manufacturers are turning to recycled polyester. Patagonia is also a pioneer here and has been processing fabrics from recycled PET bottles, plastic waste from the oceans and worn-out clothing for years. There are also many sustainable sneaker labels, which make running shoes from recycled polyester. No new petroleum needs to be used for the recycled fibers and they are not inferior to "new" fibers. However, it's important to remember that this doesn't solve the microplastic problem, and the recycling process also requires a lot of energy. In addition, recycling plastic has limits; PET cannot be endlessly reused. And it is currently hardly possible to recycle polyester from blended fabrics.