What is polyester?
Polyester is a manmade fibre, synthesized from petrochemical products by a process called polymerization. It is derived from crude oil petroleum and is a non- renewable resource. It is processed through a system called ‘cracking’ which treats the petroleum through intensive heating and cooling, fuel, solvents, pressure and catalysts to break down the molecular structure.
Once polymerized, polyethylene terephthalate PET (think water bottles) is created in a liquid form. This liquid can then be extruded, dried and chopped into small pellets and is ready to be melt spun through industrial spinnerets. Once cooled and hardened, it forms a polyester yarn that can then be woven into a textile. Although most sources are petroleum-based, some alternatives include recycled plastic (most commonly referred to as rPET), or bio-based polyester from agricultural crops or waste.
Recycled Polyester
Polyester can be either mechanically or chemically recycled using pre or post-consumer waste. However, according to the Textile Exchange Preferred Fibre Materials Report 2017, only 7% of all polyester used is recycled. When chemically recycled, the PET flakes are broken down into the base chemical molecule, which then goes back into the original polyester manufacturing system.
The most common form of recycled polyester is known as rPET, which comes from discarded clear plastic bottles instead of raw petrochemicals. Polyester fabric recycling, where the actual polyester yarn is recycled, is less common. In this case, scraps and textiles are broken down into fibre components that can then be spun into the recycled yarns.
Why use Polyster?
Polyester is a lightweight, wrinkle-resistant fibre that is durable and long-lasting, making it ideal for everyday and performance wear. Its stain-resistant and low-absorbency nature allows for fast drying, while its low impact on resources—requiring less water, energy, and heat for washing—enhances its practicality and eco-friendliness.
Its versatility makes it suitable for a wide range of applications, from clothing and sportswear to home textiles and industrial uses. Choosing polyester ensures a cost-effective, durable, and low-maintenance material that meets the demands of modern lifestyles.
The rPET Recycled Polyester Process
1. Selection | PET bottles are selected and sorted into bales at recycling centres and then sent to specific PET recycling facilities. Clear bottles are selected for their neutral base that allows for dying. |
2. Cleaning | The bottles are cleaned, labels and caps removed. Steam and chemicals help wash and remove labels while infrared NIR equipment and metal detectors further remove any non-PET components. |
3. Shredding | The bottles are shredded into flakes using a mechanical bale breaker. The flakes are cleaned once again and thoroughly checked so they have zero impurities. |
4. Processing | They go through a de-polymerisation and re-polymerisation process to be turned into PET chips. These PET chips or pellets can be used to make clothing, insulation, new water bottles, etc. |
5. Melting | The pellets are then passed through a spinneret and melted and cooled into fibers, which are then smoothed, stretched and placed on reels in order to make yarn. |
6. Recycled Polyester Yarn | The yarn is ready to be used and woven or knitted into fabric again, and has the same aesthetics and functional performance as conventional polyester yarn. |
Image Credits: Wstar apparel
Environmental Impact of Polyester
The production and use of polyester have significant environmental consequences. While polyester does not require agricultural land or water, it is energy-intensive, producing nearly three times the greenhouse gas emissions of cotton. It relies heavily on non-renewable fossil fuels, linking it to oil extraction, and is non-biodegradable, with most polyester products ending up in landfills.
Furthermore, polyester sheds microplastics during washing, contributing to ocean pollution and disrupting ecosystems. Recycling polyester is an option, but only 7% of polyester used globally is recycled, with the most common form being rPET from discarded plastic bottles.
Key Sustainability Challenges include:
- High energy use and greenhouse gas emissions during production.
- Microplastic pollution from fibre shedding during washing.
- Limited adoption of polyester recycling, with fabric recycling being less common.
How to Improve Sustainability in Polyester Production
1. Opt for Recycled or Bio-Based Polyester
Choose recycled (rPET) or bio-based polyester to reduce environmental impact. Recycled polyester uses 30-50% less energy compared to virgin polyester and diverts waste from landfills. It also has a broader positive environmental impact with an estimated 2.9 billion plastic bottles being diverted from landfills in 2016 to be recycled back into polyester yarns.
2. Improve Traceability
Focus on bio-based or recycled polyester, which allows for better supply chain transparency using emerging technologies.
3. Use Mono-Materials
Design with 100% polyester rather than blends to facilitate mechanical recycling. Avoid blending biodegradable fibres (e.g., cotton or wool) with non-biodegradable ones like polyester, which complicates recycling.
4. Encourage Responsible Washing
Promote care labels highlighting that polyester does not need dry cleaning, can be washed in cold water, and dries quickly. Advocate for less frequent washing and the use of tools like GuppyFriend laundry bags or Cora Balls to reduce microplastic release.
5. Enable Post-Consumer Recycling
Implement take-back schemes to close the loop, ensuring used polyester is recycled or reused. Design products for durability and recyclability to minimise waste. By addressing these issues and adopting these strategies, polyester can become a more sustainable choice in the fashion industry.
Key certifications for Polyester include:
- Recycled Claim Standard
- Global Recycled Standard
- OEKO-TEX Standard 100
Obtaining these certifications will help capture the increasingly eco-conscious customer base, emphasising your company’s commitment to sustainability. In 2023 a CBI study highlighted that 69% of German consumers consider environmental impact when purchasing clothing, with materials used being a primary criterion for determining a product’s eco-responsibility. This suggests a trend with the European market turning to the usage of sustainable and recycled materials.
How can SupplyScope help?
SupplyScope is your all-in-one product development, compliance, and sampling management platform. Streamline the way you manage your products, suppliers, and compliance to bring high-quality products to market faster.
With SupplyScope’s Fashion PLM, you can:
- Create digital tech packs for seamless sharing of product specifications.
- Boost efficiency by utilising a reusable card framework for key components.
- Leverage ready-made templates for everything from materials to labels.
- Track product changes and communications on a single, centralised platform.
- Build your tech pack and manage sampling processes with precision and clarity.
Additionally, if you are considering establishing a material library for managing your product line, SupplyScope offers the tools to centralise and organise your materials, ensuring you have full visibility and control.
Empower your team to innovate and collaborate with ease. Unlock their full potential with SupplyScope.