Cotton and Polyester
There are many different clothes in our closets, but we often do not know how, where and what they were made of. Clothing made of cotton and synthetic fibres, such as polyester, are widespread. In order to act in an environmentally, energy and resource-saving manner, the entire textile chain must be brought into focus. Both materials are problematic in their own way, whether in production or in use.
If we refer to a cotton or a polyester T-shirt for this comparison, a difference in fabric consumption becomes immediately apparent. A cotton T-shirt weighs 300 grams, while an identical shirt made of polyester weighs about 200 grams, i.e. 1/3 less.
The production of the cotton shirt requires about 2000 litres of water for the irrigation of the fields, the cleaning of the cotton and the finishing. Roughly speaking, a kilo of cotton fibres requires a total of about 10,000 litres of water, whereas a pair of jeans alone can weigh around 800 grams. This differs regionally, with water consumption in China being much lower than, for instance, in India.
In contrast, less water is needed to produce a polyester T-shirt. However, this does not mean that it is the better choice, because the non-renewable raw material crude oil is needed for its production. If recycled plastic is used, it must be melted down and then processed into yarn. In this case, in Asia, T-Shirts are made out of about eight plastic bottles but therefore transport is necessary, which again worsens the environmental balance.
The energy balance of the two materials cotton and polyester are almost similar. However, since the latter has a lower fabric content, correspondingly less energy is required. In use, polyester seems to have something ahead of cotton. The synthetic fibre is easier to care for because it requires less heat in the washing machine, dries faster and does not need to be ironed. Cotton, on the other hand, has a shorter life, shrinks faster, it is often washed hotter and more ironed. Nevertheless, synthetic fabrics release micro plastic particles through abrasion when washed, which are released into the environment.
To ensure a completely sustainable textile chain, it would be desirable if every single garment was returned to its cycle: For (organic) cotton into a biological cycle and for polyester into a technical cycle. Organic cotton is almost 100% biodegradable. Chemical treated fibres may remain due to dyeing and printing of the clothing, but it is compostable and decomposes after a relatively short time. Polyester, on the other hand, does not decompose. In order not to produce waste, new products must be created through recycling, e.g. bottles, toys and other items made of plastic. It is also possible to create new clothing from recycled polyester, but this would require transport to Asia, which would result in a worse environmental balance.