What is Lyocell?

Lyocell is a regenerated cellulose fiber made by dissolving cellulose in an organic solvent, without forming a derivative, and spinning it. The EU fiber-name list defines lyocell as a regenerated cellulose fiber obtained by this process (Regulation (EU) 1007/2011, Annex I). The commercial solvent is NMMO (N-methylmorpholine N-oxide). The process of the first pilot plant, set up in the UK in 1982, was later developed into full-scale commercial production under the “Tencel” brand name; Lenzing became the largest lyocell producer by acquiring Tencel Group in 2004 (Zhang et al., 2018). Lenzing still describes itself as the global leader in lyocell production (Lenzing, 2025).

How lyocell is made

Production has five steps: dissolving, filtering, spinning, washing and finishing (Zhang et al., 2018). Cellulose is physically dissolved in a mixture of NMMO and a small amount of water; the mercerization, aging and carbon disulfide xanthation steps of the viscose process do not exist. Before the spinneret the solution is pushed through an air gap and then into a coagulation bath (dry-jet wet spinning). In the air gap the fibers become oriented; according to the review, this high orientation is one of the main contributors to fiber strength. More than 99% of the solvent can be recovered, but recovery requires high energy.

Properties of lyocell

• Strength: It is about twice as strong as viscose when dry and about three times as strong when wet. It keeps most of its strength when wet, whereas viscose loses about half. Elongation at break is lower than viscose (Zhang et al., 2018).
• Comfort properties: The same review reports that lyocell is superior to viscose in softness, absorbency, breathability, shape stability and dyeability.
• Moisture: For fiber-content calculations, the EU regulation sets an agreed allowance of 13% for lyocell, as it does for viscose and modal (Annex IX).
• Fibrillation: During wet abrasion, fine fibrils can open up on the fiber surface; this is called fibrillation. It is controlled through spinning conditions, alkali treatment, reactive dyeing, cross-linking agents and enzyme treatments (Zhang et al., 2018); in other words, it is a property managed in finishing and dyeing.

Where is lyocell used?

In apparel it is used in denim, chinos, underwear and casual wear; in home textiles in products such as towels, bedding and sheets. Nonwoven products such as wipes, medical gauze and filters are also made from lyocell fibers (Zhang et al., 2018). You can find lyocell and other regenerated cellulose fiber suppliers in the Textile Fibers category, and viscose and similar cellulosic yarn suppliers in the Viscose Yarn category.

Lyocell, Tencel, modal and viscose

• Viscose: Viscose is made with carbon disulfide and an acid bath, lyocell with NMMO and an air gap. Viscose loses about half of its strength when wet; lyocell keeps most of it.
• Modal: It is made by a modified viscose process and is a separate process from lyocell. In the EU list all three are separate fiber names.
• Tencel: A Lenzing brand, not a fiber. Lenzing sells three fibers under it, TENCEL™ Lyocell, TENCEL™ Lyocell Filament and TENCEL™ Modal (Lenzing, 2025), so a label that just says “Tencel” leaves open whether you are getting lyocell or modal. Verify the fiber name from the composition line.
• Under the microscope: In electron microscope images, viscose has a rough surface and an oval cross-section, whereas lyocell has a smooth surface and a round cross-section (Zhang et al., 2018, Figure 4). This difference is for laboratory examination; do not try to tell fiber types apart by touch.

Care

Some lyocell garments can be machine washed and dried, others need dry cleaning; check the label first. For machine-washable products low-temperature washing is recommended; remove from the dryer as soon as it finishes and, if ironing is needed, use medium heat (FabricLink).

Frequently asked questions

Are lyocell and Tencel the same?

Lyocell is the fiber name; Tencel is Lenzing’s brand name. The Tencel brand is used not only for lyocell but also for modal.

Is lyocell synthetic?

No. The raw material is plant cellulose; the fiber is obtained by dissolving the cellulose in a solvent and re-forming it. That is why it counts as a regenerated cellulose fiber, like viscose and modal.