In the 1940s, the first polyester fibres emerged, known as Terylene in the US and Dacron in the UK [1]. It was in the 1950s that polyester fibre production gained momentum on a commercial scale [2]. The 1990s marked a significant growth in polyester production, a trend that has continued vigorously since then [3]. Thanks to its versatility and competitive pricing, polyester is the second most essential textile worldwide, commanding approximately 30% of global production [2]. Notably, 69% of all polyester production occurs in China [4], with China, India, and Southeast Asia collectively contributing to 80% of the world’s polyester production.
Photo: Love to Know
Polyester is strong, tough, abrasion resistant, with good recovery properties, and does not absorb much moisture [2]. These properties contribute to polyester’s dimensional stability and resistance to wrinkling, even when washed at temperatures below 60 degrees. Polyester is often used in blends with other textiles, such as viscose, wool and cotton, to reinforce the fabrics and contribute to polyester’s wrinkle-resistant properties [5].
Polyester is typically derived from the plastic PET (polyethene terephthalate) [2], which is a type of polymer—a chain-like molecule produced through chemical polymerization, where small molecules are interconnected to form larger ones [6]. During manufacturing, PET starts as plastic pellets, which are melted, pressed, and extruded into fibres through a melt-spinning process. This process can also involve incorporating matting agents, colour pigments, and flame retardant additives to modify the properties of the polymer blend [1].
Photo: Paul Stewart – Textile Technologies
Polyester is a synthetic fibre, mainly based on petroleum, also called crude oil, a fossil fuel and raw material [7]. Petroleum is not biodegradable and will be stored in ecosystems [3]. Astonishingly, over 70 billion oil barrels are used annually in polyester production. In terms of energy consumption, polyester is more efficient than nylon but requires twice the energy needed for conventional cotton. Every kilogram of woven polyester generates over 27.2 kg of CO2 equivalent emissions.
An essential step in more sustainable polyester production is to phase out the use of oil as a material for PET and an energy source for production [3]. We can produce PET from recycled materials or renewable resources such as carbon dioxide and biomass. For example, carbon dioxide is converted into chemical building blocks for polymers through carbon sequestration, but more research is needed to optimize the technology. On the other hand, the use of biomass has increasingly emerged in the industry, but its economic benefits are currently limited. Therefore, less than 1 % of PET production in 2018 is biomass-based.
Polyester based on biomass does not necessarily mean less impact on the environment [3] as it depends on the type of bioresource, how we produce it, and the energy source we use [8]. For example, biomass from corn and sugar cane can have as high emissions as polyester based on oil due to the increased land use and resource depletion from these biomasses [3]. Recycled biomaterials are more environmentally friendly, such as orange peels from food waste. However, biomass-based polyester is also not biodegradable like the fossil-based one and contributes to microplastic emission [9].
When fabrics are dyed, a large amount of water is required; polyester must also be heat treated after dyeing, partly because of its water-repellent properties so that the colour pigments can penetrate the fabric [3]. This results in over 2.31-4.14 kg of CO2 eq emissions per kg of dyed textile. Due to poor management of residual waste generated in the production steps of polyester, it contributes to water and soil pollution through the release of wastewater. The wastewater containing dyes and chemicals is discharged into nearby waterways, adversely affecting the environment.
While water usage in polyester production is lower than that in natural textiles, it’s important to note that natural dyes, which have a lower environmental impact, cannot be employed for dyeing polyester. Consequently, the negative impact on water resources remains relatively high [7].
A large part of the microplastics released into the environment comes from synthetic fibres, and polyester is considered the biggest polluter among them [10], [11]. Plastics do not biodegrade but decompose into smaller pieces called microfibers, microplastics or microplastic fibres [12]. Microplastics have a long residence time in sewage systems and are difficult to capture, making them easily spread to waterways, lakes and oceans [13]. The main problem with microplastics is that once they are released into marine environments, there is no practical way to remove them; they accumulate in the food chain, are toxic to animals, and, like a sponge, attract other toxic substances in the water [14].
Synthetic textiles such as polyester release microplastic fibres through wear and tear, which occurs when we use, wash and dry the clothes [15]. Fabric blends with synthetic and natural fabrics are believed to release fewer microfibers than pure polyester. However, fabric blends are not optimal for possibly recycling the material [10]. Recycled or second-hand clothes are the most environmentally friendly polyester alternatives [3]. Recycled polyester requires less energy to recycle than it takes to produce brand new [16]. The primary recycled polyester sources are PET bottles and residual waste from production. Recycled polyester based on PET bottles increased its market value from 8 % in 2007 to 14 % in 2017 [18]. New clothes and textiles release microplastic fibres most during the first four washes [15]. One way to reduce particle emissions during washing is to follow the washing instructions on the garment, use a laundry bag that captures the particles, and reduce wear and tear on the clothes. Filters in washing machines can also be a solution to reduce the spread of microfiber plastics.
Sources
- Wired – Dacron in the United States and Terylene in Britain
- Sewport – What is Polyester Fabric: Properties, How its Made and Where
- Palacios-Mateo – Analysis of the polyester clothing value chain to identify key intervention points for sustainability
- Sciencedirect – Marine microfiber pollution: A review on present status + future challenges
- Encyclopedia Britannica – Polyethylene terephthalate (PET or PETE)
- Nationalencyklopedin (NE) – Polymerisation
- Sciencedirect – Sustainable Fibres and Textiles – Sustainable synthetic fibre production
- European Parliamentary Research Service – Environmental impact of the textile and clothing industry – What consumers need to know
- European Environmental Agency – Microplastics from textiles: towards a circular economy for textiles in Europe
- Multidisciplinary Digital Publishing Institute – MDPI – Consumer’s Perceptions and Attitudes toward Products Preventing Microfiber Pollution in Aquatic Environments as a Result of the Domestic Washing of Synthetic Clothes
- Nationalencyklopedin (NE) – Synthetic fiber
- Science Direct – The efficiency of devices intended to reduce microfibre release during clothes washing
- ACS Publications – Polyester Textiles as a Source of Microplastics from Households: A Mechanistic Study to Understand Microfiber Release During Washing
- Vox – More than ever, our clothes are made of plastic. Just washing them can pollute the oceans00654/clothes-plastic-pollution-polyester-washing-machine
- Naturvardsverket – Questions and answers about sustainable textile consumption
- Science Direct – Textiles and Environment: Woodhead Publishing India Pvt. New Delhi
May 2022, TÄNKOM | Revised May 2024 RETHINK
