Other synthetic fibres (elastane, acrylic, etc.)

1

• Fibre type: Synthetic fibres
• Main types: The most widely produced synthetic fibres worldwide are polyester and polyamide. This fact sheet covers the three other main synthetic fibres used in textiles: acrylic, elastane and polypropylene.
  Other synthetic fibres are used in the textile industry, such as polytrimethylene terephthalate (PTT), which is similar to polyethylene terephthalate (PET, used to manufacture polyester). Their production volumes are very low worldwide and they are therefore not specifically covered on this page.
• Annual global production:
  - Elastane: production increased from 1.1 million tonnes in 2020 to almost 1.5 million tonnes in 2024, and continued to represent around 1.1% of the global fibre market. 3.2% of production comes from recycling (this share has increased since 2020, when it stood at 2.3%). Note: although volumes are relatively low, elastane is present in many garments, in small quantities. Growth in its production is notably driven by the rise of sportswear, including for everyday use.
  - Acrylic: acrylic represents a market share of 1.2%, including 0.8% for recycled acrylic. Its production is declining over the years, as this fibre tends to be replaced by polyester.
  - Polypropylene: polypropylene represents a market share of 2.4% (3.2 Mt), including 0.4% for recycled polypropylene. Its production has been relatively stable for several years, but is mostly intended for non-clothing uses.

• Main producing countries:
  - For elastane: South Korea (30%), China and Japan 2
  - For acrylic and polypropylene: Asia-Pacific (68.10%), particularly China3 4
  
• Share of global synthetic fibre production: The combined production volumes of these three fibres represented 5% of global fibre production in 2024.
• Fossil-based share: Between 96.8% and 99.6%, depending on the fibre, based on the share of production from recycling.

5

Elastane (also known by the trade names Spandex or Lycra®)

Elastane is a synthetic fibre renowned for its elasticity. Able to stretch several times its original length before returning to its initial shape, it is generally used in small proportions in textiles to improve comfort and fit.

Its main properties are as follows:

• Very high stretchability and short-term elastic recovery
• Comfort and freedom of movement
• Lightweight and flexible
• Compatible with many fibre blends (cotton/elastane, polyester/elastane, polyamide/elastane, etc.)

It is used in many textile products, often in proportions ranging from 2% to 10% of the composition:

• Sportswear and fitness clothing (leggings, sports bras, compression garments)
• Swimwear
• Underwear and lingerie
• Stretch casualwear (trousers, T-shirts, shirts, etc.)
• Socks and tights

Despite being present in small quantities in finished products, it can block recycling. Indeed, when elastane accounts for more than 5% of the composition, it is a disruptor for product recycling and may even completely hinder the recycling process. 6

Alternative elastic materials to elastane exist :

• modified elastanes, which retain the mechanical properties of elastane while improving their source (more circular) or their end-of-life.

In addition, elastic materials of a different chemical nature offer complementary solutions, such as :

• Elastolefins, chemically similar to polypropylenes and polyethylenes.
• Elastodienes (natural elastomers such as rubber, or synthetic elastomers), mainly used for technical applications such as tyres or seals (very rarely in textiles: covered yarns).
• Materials from the polyester family: elastic due to the conformation or texturing of the fibre (through processing):
  - PBT (polybutylene terephthalate) and PTT (polytrimethylene terephthalate): thermoplastic materials with intrinsic elasticity;
  - Elastomultiesters (or EME: polyester copolymers).

Acrylic 7 
Acrylic is a synthetic fibre often used as an alternative to wool. It offers good thermal comfort while being easy to care for.

Its main properties are as follows:

• Wool-like appearance and feel
• Lightweight and soft
• Good thermal insulation
• Resistance to ultraviolet (UV) rays and weathering
• Good dimensional stability
• Easy care and quick drying
• Compatible with fibre blends (wool/acrylic, cotton/acrylic, etc.), for example to make care easier or reduce production costs

While acrylic may be seen as an alternative to wool in terms of feel and static thermal properties, it does not have wool’s thermoregulating properties (active moisture absorption, bidirectional hot/cold regulation).

Acrylic is used in many textile products, often knitted:

• Pullovers, cardigans and winter clothing
• Hats, scarves and gloves
• Blankets and throws
• Faux fur

Polypropylene 8
Polypropylene is a very lightweight synthetic fibre, recognised for its technical performance and low density. Its resistance to moisture and chemicals makes it particularly suitable for technical applications and performance textiles.

Polypropylene is mainly used for industrial and technical applications (geotextiles, nonwovens, carpets) and, to a lesser extent, in the clothing industry, for example for technical underwear and sportswear or outdoor activity clothing (including winter sports).

Stages of the production process

The production stages for the three fibres have common features, with a few differences :

Production diagram

Dry spinning

Wet spinning

Melt spinning

A diagram showing an example of a complete process can be found in the dedicated polyester fact sheet

Environmental issues of production 9 10

1. Durability 16

1. Elastane is a fibre recognised for its elasticity and its ability to return to its original shape after stretching. However, its long-term resistance can be affected by repeated exposure to heat, ultraviolet (UV) rays, chlorine or certain chemicals, which can lead to a gradual loss of its elastic properties. The progressive loss of elasticity is the main factor in the premature disposal of stretch items, even if the rest of the fabric is intact.

2. Acrylic generally allows products to retain their colours and thermal properties over time. However, its abrasion resistance is lower than that of some other synthetic fibres, and it tends to pill, which can alter the appearance of textiles after repeated use.

3. Polypropylene has characteristics that allow it to maintain its performance in technical, sports or outdoor applications, including after many use cycles. However, its sensitivity to heat and ultraviolet (UV) radiation can lead to faster degradation when it is exposed to outdoor environments over a long period without specific treatment.

For all three fibres, durability depends on the applications and conditions of use or care.

2. Recyclability 17 18

• Elastane: mainly used in small proportions in textile blends (cotton/elastane, polyester/elastane, etc.), it is very difficult to isolate during recycling. Its presence is a major barrier to currently available mechanical, thermomechanical and chemical recycling processes, although some chemical recyclers (at pilot stage, with no industrial capacity yet) have developed methods to extract it.
• Acrylic: mechanical recycling is more widely used for acrylic textiles (mostly knitted and perfectly suited to garnetting), although a few players also offer chemical recycling solutions.

For polypropylene, acrylic and elastane, textile-to-textile recycling solutions exist or are under development, but they currently remain little deployed at industrial scale

3. Incorporation of recycled materials

1. Elastane, being a recycling disruptor, a good practice is to limit the proportion of elastane in fabrics to 5%. To go further, favouring fabrics with as little elastane as possible, or even no elastane (when the product’s use allows), is beneficial from a recyclability perspective.
Using recycled elastane as a replacement for virgin elastane can help limit the use of non-renewable resources.

2. Acrylic: Using recycled acrylic as a replacement for virgin acrylic can help limit the use of non-renewable resources.

3. Polypropylene: The use of polypropylene can be reserved for technical applications where its properties are irreplaceable. For other uses, it can in some cases be replaced by other synthetic fibres from recycling.

Several labels and certifications exist for this material; the following are eligible for Refashion’s “Environmental Labels” eco-modulation.

Eco-modulations: Refashion promotes product eco-design approaches through a system of premiums and penalties. Discover the criteria and procedures for declaring eco-modulations.

Find out more