Artificial and cellulose fibres

Man-made cellulosic fibres occupy an intermediate position between natural and synthetic fibres. They are derived from plant cellulose, an organic compound found in plant cell walls, most often from wood pulp, but require extensive chemical processing—dissolution, esterification or another chemical reaction depending on the type of fibre—in a solvent in order to be spun 1. This processing gives them characteristics similar to those of natural fibres, but at a lower cost.

Man-made cellulosic fibres belong to the category of man-made fibres, in the same way as man-made protein fibres (casein, soy, zein), which will not be covered in this factsheet.

• Fibre type: Man-made cellulosic fibres, or MMCF (Man-Made Cellulosic Fibers). What distinguishes these fibres from one another is the cellulose transformation process:
  - Regenerated cellulose fibres (viscose, modal, lyocell and cupro) 2: involve the cellulose being dissolved and then regenerated in a new crystalline form.
  - Modified cellulose fibres (acetate, triacetate)3 : here, the cellulose is esterified by reaction with acetic anhydride (a reaction with acetic anhydride that makes the cellulose less sensitive to water and thermoplastic) and remains chemically transformed in the final fibre. It is the degree of esterification that distinguishes acetate from triacetate.
• Annual global production: Annual global production of man-made cellulosic fibres has been increasing for 30 years. This production has more than doubled since 1990, when it amounted to just over 3 million tonnes, reaching around 7.1 million tonnes by the end of the 2010s. After a temporary decline in 2020 linked to the Covid-19 pandemic (6.5 million tonnes), production rebounded to 7.2 million tonnes as early as 2021, before reaching 7.9 million tonnes produced in 2023 and 8.4 million tonnes in 2024 4. Viscose accounts for 80% of man-made cellulosic fibre volumes, followed by acetate/triacetate and then lyocell, with 13% and 5% of volumes respectively. 5

• Principaux pays producteurs et acteurs  6: En amont, la production de pâte à dissoudre (pâte de cellulose obtenue à partir de bois avec un taux très élevé de cellulose) est concentrée en Afrique du Sud, Indonésie, Brésil, Etats-Unis et Chili. En aval, près des deux tiers de la transformation s’effectue en Asie, notamment en Chine, Indonésie et en Inde qui figurent parmi les plus gros importateurs de pâte à dissoudre.
• Place dans la production mondiale de fibres : les fibres artificielles cellulosiques occupent la 3ᵉ place avec 6 % de la production mondiale derrière le polyester (59%) et le coton (19%). 7

Man-made cellulosic fibres are used in a wide variety of textile products:

• Clothing: linings, lingerie, dresses (viscose, acetate, triacetate). Lyocell and modal are versatile materials used for clothing such as denim, t-shirts and tops.
• Household linen: bed linen (lyocell).

Common properties: Regenerated cellulosic fibres share good moisture absorption and management, good breathability and a soft feel with natural cellulosic fibres.

Distinctive properties 8: The fibres differ mainly in their resistance to moisture, which has historically been viscose’s weak point, as it loses around half of its strength when wet. Lyocell retains a certain level of moisture resistance; in fact, it is the only regenerated cellulosic fibre whose wet strength exceeds that of wet cotton. Modal, produced using the same basic process as viscose, has significantly better resistance to stretching and moisture than viscose, allowing machine washing without deformation. Triacetate stands out for its ability to be thermoformed (pleating), but has lower abrasion resistance.

Stages of the production process

Production diagram

Environmental issues of production

1. Durability

1. The role of crystalline structure 

The durability of cellulosic fibres depends directly on the crystalline structure of each fibre. Crystalline regions are the portions of the fibre where the cellulose chains are perfectly aligned and tightly bound together, forming a compact structure that resists water infiltration and mechanical deformation. This crystallinity depends primarily on the dissolution and regeneration process used; for example, lyocell has a significantly higher crystallinity (80%) than viscose (41%) and modal (49%). This means that viscose is more prone to shrinkage, loss of shape over time and faster degradation. This high crystallinity allows lyocell to better tolerate machine washing at low temperature, making it the easiest-care man-made cellulosic fibre. Conversely, acetate is sensitive to heat and certain solvents, so dry cleaning is often recommended for this fibre. 26

2. The importance of care

Appropriate care significantly extends the lifespan of these fibres: hand washing or using a delicate cycle with a reduced load, limited spinning, air drying rather than tumble drying, and ironing at low temperature with a damp cloth. These recommendations, common to viscose and modal, limit fibre swelling and dimensional deformation, which make them more fragile.

2. Recyclability

1. Mechanical recycling : As with other fibres, mechanical recycling (shredding, garnetting) remains possible, but it shortens the fibres with each cycle, limiting outlets to lower-value applications as the cycles accumulate. It should be noted that mechanical recycling of man-made cellulosic fibres can be complex: viscose and lyocell are favoured for lightweight, fluid fabrics woven with fine yarns, which makes them very difficult to garnett.
2. Chemical recycling: he advantage of man-made cellulosic fibres lies in their ability to use cellulosic textile waste, particularly cotton, as an alternative raw material to virgin dissolving pulp. This recycling remains more complex than virgin fibre production, as it requires a purification stage to remove dyes, finishes and other fibres present in the used textile 27. his is the principle behind the technologies that are currently the most developed at pilot or industrial scale: Circulose, Refibra, NuCycl and Infinna transform cotton-based textile waste into new regenerated cellulosic fibres. Chemical recycling of man-made cellulosic fibres into new man-made cellulosic fibres, for example from used viscose or modal into new fibre, remains a much less mature route, as illustrated by recent work on the Ioncell process, which redissolves already degraded viscose and modal fibres in an ionic liquid in order to spin them again into new lyocell-type fibres 28. The main challenge for these sectors remains production costs, which are higher than those of virgin fibre, slowing their large-scale adoption.

3. Incorporation of recycled material

Recycled dissolving pulp is now a secondary raw material that is increasingly being studied in the man-made cellulosic fibre industry. Its incorporation into new fibres makes it possible to recover cellulosic textile waste while reducing the consumption of virgin dissolving pulp.
In recent years, progress in purification and dissolution processes has helped improve the quality of recycled pulp, in particular by limiting the cellulose degradation traditionally associated with this type of recycling. At the same time, emerging dissolution processes are exploring the transformation of already highly degraded fibres, such as used viscose or modal, into new lyocell-type fibres.
These advances are gradually expanding the outlets for recycled material, although it is still generally blended with virgin pulp in order to preserve the mechanical properties of the final fibre.

Considering the environmental issues specific to cellulosic fibres, there are two relevant types of certification. Those focusing on the upstream stage, particularly the origin of raw materials such as wood, and those aimed at reducing the impact of production process stages and the use of chemicals.
There are several labels and certifications for this material; here are those eligible for Refashion’s “Environmental Labels” eco-modulation. 29 30 31 32

Eco-modulations: Refashion promotes product eco-design initiatives through a system of bonuses and penalties. Find out about the criteria and procedures for declaring eco-modulations.

Learn more

Alternative materials available :

Alternative fibres: to produce a man-made cellulosic fibre, resources other than wood can be used, including next-generation fibres (Next Gen Fibers), which refer to man-made cellulosic fibres produced from post-consumer textile waste or raw materials that are alternatives to virgin forests. These include cotton linter (a ginning residue, used in particular for cupro), wheat, oat or rice straw, sugarcane bagasse, and post-consumer textile waste, which enters the chemical recycling streams discussed above. These alternatives can be of interest by recovering agricultural co-products or offering faster yields than wood, with a smaller land footprint. However, this observation must be qualified, as it depends strongly on the type of agriculture practised: any alternative raw material must undergo an LCA before it can be presented as more virtuous—the impact depends on the agricultural context, location and method of recovering the co-product. 33
Less impactful processes: Lyocell uses a manufacturing process recognised as less impactful than viscose and modal, since the solvent in which the pulp is dissolved (NMMO) is recovered at more than 99% and then reintegrated into the process in a closed loop, a level of recycling that neither viscose nor modal achieves 34. It is also non-toxic and non-corrosive, and has reduced water consumption. In addition, the wood used is largely eucalyptus, a fast-growing species that enables shorter rotation cycles and a higher yield per hectare than European species such as beech. However, the impact should still be qualified, since eucalyptus monoculture plantations significantly reduce biodiversity.