How recycled polyester transforms our waste into clothes

Reduce waste, energy saving, new way of designing,…, How does recycled polyester force us to rethink design phases?

Recycling polyester constitutes an interesting avenue to reduce the textile industry's environmental impact. The idea is to reuse what already exists instead of extracting new raw materials. It seems logical enough as an idea…, but in actual fact, it is a little more complicated. For recycled polyester to be a viable alternative, a number of technical and economic hurdles have to be overcome. The aim is to ensure that recycled fibres retain their technical features, and are as strong and durable as fibres made from virgin material, all at a reasonable cost with the end product remaining affordable. There lies the real challenge: turning a promising idea into a tangible and workable reality.

The process of recycling polyester

As with clothing in general, there are two to three main methods for recycling polyester: mechanical, thermal and chemical recycling.

- Mechanical recycling: It consists of unravelling textile fibres (or other waste, such as plastic bottles - PET). This technique preserves the material's initial aspect (a green fibre, for example, remains green) and applies to both natural and synthetic fabrics.

- Thermomechanical (or thermal) recycling: mainly used for synthetic materials such as polyester and polyamide, involves melting and then extruding the material to create new fibres. As with mechanical recycling, this technique also preserves the original appearance.

- Chemical recycling: Applicable to natural and synthetic materials, it consists of depolymerising the material, in other words, breaking it down into its base elements to then reconstruct virgin fibres. It is a little bit like when making pastry.

Please note: Mechanical and thermal recycling can deteriorate the material. That is why the proportion of recycled material used in an item generally varies between 30% and 70%, depending on the intended use. The more it is subject to mechanical wearing, the less recycled materials it may contain (for example, a t-shirt, subjected to regular friction, to frequent washing, etc., will include a lower proportion of recycled fibres than a pair of curtains, which are subject to less wear & tear).

How does recycled polyester transform our waste into clothes

Key figures for recycled polyester

In Europe, 87 % % of collected used clothing is incinerated or disposed of in landfills.

Only 1 % of used clothing is recycled into new clothes. By using old textiles to produce new ones, we reduce the consumption of virgin materials.

Textile production is estimated to be responsible for approximately 20 % of water pollution worldwide due to dyeing and finishing.
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Using polyester yarn from textile waste helps to reduce the environmental impact by 23 % compared to virgin polyester yarns.
(Source : PEF methodology, Database EF3.1)

How is post-consume polyester made work?

Post-consumer recycling focuses on materials that have already been used, such as clothes or products made of polyester. While DECATHLON initially mainly used recycled polyester made from plastic bottles, it is now also turning to textile waste.

The first stage consists of collecting this waste. Various channels exist, such as sorting centres, in-store collection or buyback schemes offered by certain brands. Once collected, these textiles are sorted by colour and composition to separate the polyester from the other materials. It is then necessary to meticulously clean them to eliminate impurities such as food or dirt.

Today, in 2025, post-consumer recycling, does not yet represent the majority of recycled polyester used by DECATHLON. This is down to the complexity of a sector, which still needs to be structured and optimised. Collecting, sorting and processing post-consumer textile waste require investment and innovation to guarantee the quality and traceability of recycled materials.

The advantages of recycled polyester

Using plastic waste, such as plastic bottles or used clothing, to produce new textiles allows the industry to reduce its reliance on fossil resources. Unlike virgin polyester derived from fossil fuels, recycled polyester uses existing resources, reducing CO2 emissions linked to its production.*

*There is a -23,62% reduction between virgin polyester yarn versus recycled polyester yarn made from textile waste (a mixture of post-consumer and pre-consumer) (source: Textile Exchange).

On top of reducing greenhouse gas emissions, turning to recycled polyester helps to recycle waste that would otherwise end up being incinerated or in a landfill. It's an approach, part of a circular economy rationale, where materials are reused and recycled wherever possible.

Mixed polyester:a recycling challenge

A significant hurdle to the widespread use of recycled polyester is mixed fibres. Clothing made with polyester is often combined with other materials, such as cotton or elastane, to improve their comfort or elasticity. While these mixed textiles are convenient for consumers, they considerably complicate the recycling process, as each material needs to be separated so it can be reused.

Technological innovation seeks to meet this challenge. Advanced processes now allow the recycling of some mixed polyester while preserving the features of the end product fabric. However, these techniques remain costly and require more research to reach the threshold of large-scale application. Actually rethinking production is then about revisiting the clothes design from the outset, opting, for example, for materials that are simpler to recycle. It is the principle behind eco-design.

The use of recycled polyester at DECATHLON

As part of its impact reduction strategy, DECATHLON started the adventure of recycled materials in 2012 by integrating them into clothing fabrics made from post-consumer bottles. Aiming to continue reducing its environmental impact, DECATHLON has chosen materials from recycling, manufacturing cutting scraps and post-consumer waste.

Dedicated teams focused on raw materials, whether they be synthetic or natural. Initially formed to control the value chain and guarantee the quality of end products, these teams have gradually integrated an environmental dimension to their mission, as part of an eco-design approach. Until 2019, the main goal was to replace virgin polyester with recycled and/or solution-dyed polyester.

Since 2019, DECATHLON has been integrating recycled cotton from its own manufacturing offcuts. The company also started to use recycled polyester from clothing, combining manufacturing cutting scraps (pre-consumer) and end-of-life products (post-consumer) in a proportion of 80% / 20%.

Three waste categories are identified:
- Post-consumer : used products collected after use by the consumer. Some will be given a new lease of life through the second-hand market, while the remainder will be recycled.
- Pre-consumption: Unsold stock (not used by DECATHLON).
- Pre-consumer: manufacturing scrap materials generated during yarn or fabric production or garment assembly (although this part should decrease if the Minimal Waste Design becomes more widespread).

Until now, DECATHLON prefers using pre-consumer waste because it offers better traceability and a known composition, making recycling easier.

The challenge of recycling post-consumer waste

Post-consumer waste presents a significant challenge because it is made up of a mixture of fabrics. It is therefore necessary to develop technologies that help to effectively separate and recycle the different components.

DECATHLON has invested since 2021 in research and development to find recycling solutions adapted to these complex textiles. Polyester and cotton are the priority, given they represent 95% of DECATHLON's clothing range.

As a result, DECATHLON has formed a partnership with a French start-up, Recyc Elit, which specialises in chemical polyester recycling. The aim being to develop innovative solutions to sort and recycle textiles by materials and colour, along with speeding up innovation and structuring the sector. The objective is to establish a sustainable ecosystem for recycling textiles.

In seeking to better recycle, DECATHLON has also learnt to better design its products. The goal is to create clothes that will be easier to recycle at the end of their life cycle. Real teamwork to achieve actual circularity from design through to the end of the product's life cycle!

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