What is polyester and why is it really bad for the environment? In this article, we dive into one of the most common materials in our clothes - and why recycled polyester is the better option.
Polyester is one of the most common materials in our clothes. Conventional polyester is a synthetic fiber based on petroleum (crude oil), just like plastic is. Crude oil is a fossil fuel that remains in the ecosystem because it is not biodegradable. From a sustainability perspective, conventional polyester is considered really bad.
But to avoid the oil extraction that the production of new polyester requires, other types of already existing plastic products can be recycled, for example, PET bottles. Using PET bottles to produce recycled polyester saves large amounts of energy, Co2, and water compared to the production of conventional, new polyester, and you also bypass the use of crude oil which participate in the oil extraction industry, which is the biggest contributor to climate change. Textiles made of synthetic fibers also release microplastics when they are washed, which risks being carried along with the water and ending up in nature.
So how is recycled polyester made?
Recycled polyester is made from old PET bottles, through a mechanical or chemical process. Mechanically recycling PET bottles is done by sterilizing, drying, and then crushing the PET bottles into small chips. The slivers are then heated and eventually become yarn, which is then woven into a fabric. This is the most common method.
The chemical process involves cleaning and shredding the PET bottles into small plastic chips. The plastic then undergoes something called depolymerization, which is a process of chemical reactions that convert the plastic into monomers (the basic building blocks of plastic). Recycled polyester is created by polymerizing the monomers back into plastic.
The plastic that is used can either be "post-consumer", i.e. recycled after it has been used (PET bottles), or "pre-consumer", recycled before it even reaches the market (residues and waste from production).
Advantages of recycled polyester
The advantages of choosing recycled polyester instead of conventional are thus many. No oil is required during production, it saves energy, Co2, and water and it is made from plastic (bottles) that would otherwise have risked ending up in landfills or out in nature.
Criticism of recycled polyester
That recycled polyester is better than virgin polyester is pretty obvious. But how good is recycled polyester in the grand scheme of things? The criticism against clothes made from old PET bottles is based on several things. First, recycled polyester clothing cannot be recycled, meaning that when PET bottles are "transformed" into clothing, it is the last stop on the life cycle. From an environmental perspective, it is therefore better to use old plastic bottles to make new plastic bottles. In this way, the material can be reused several times, which reduces the number of new (virgin) plastic bottles. Worth mentioning is that this is currently more wishful thinking than actual practice. Not all bottles are recycled into new bottles, but this type of "closed-loop recycling" (bottle to bottle) is developing everywhere in the world, which means that we must ensure that this development is not undermined by the recycling of PET bottles into polyester fiber.
Making clothes from recycled polyester also contributes to the spread of microplastics. Microplastics are released from the clothes we wear and spread through the air, water, and food and thus end up in people, animals, and nature. However, there are ways to reduce the spread of microplastics. The obvious solution is of course not to consume clothes made of polyester, but by following special washing advice, for example using a Guppy Friend, it is possible to protect the environment even though the clothes are not environmentally friendly in themselves. Read more about how to take care of clothes in the best way in our Laundry Advice and Care Instructions.
The very term recycled polyester is also used for marketing purposes as a kind of greenwashing technique. Then it is mainly about marketing the clothes as 'green', 'environmentally friendly', and 'sustainable' with the argument that it is ok to consume clothes made of recycled polyester because they are not harmful to the environment. Then it's about highlighting all the advantages, without mentioning any of the disadvantages.