Lyocells

Lyocells are a class of regenerated cellulose fibers used in textiles. They are produced from dissolving pulp derived from wood and are marketed under various brand names, most prominently as lyocell fibers. The term is often used to describe the fiber produced by the lyocell process, a solvent-based method for dissolving cellulose.

The production of lyocell relies on N-methylmorpholine N-oxide (NMMO) as a direct solvent. Dissolving pulp is dissolved in NMMO at elevated temperature to form a viscous dope, which is extruded through spinnerets into air or a coagulating bath where cellulose reforms into fibers. The solvent is recovered in a largely closed-loop system and reused, minimizing emissions and waste. This process is contrasted with older cellulose fibers that used more hazardous chemical routes.

Lyocell fibers are valued for a combination of properties. They typically exhibit high dry and wet strength, strong abrasion resistance, and excellent moisture absorption, giving a soft, breathable, and smooth hand. They have good drape and dye affinity, and can be produced in various thicknesses and finishes. Lyocell blends with other fibers, such as cotton, polyester, or elastane, to tailor performance for different applications.

Common uses include apparel—shirts, dresses, underwear, and activewear—and home textiles such as bedsheets and towels. Lyocell is also used in some nonwovens and specialty fabrics.

Sustainability considerations include the use of renewable wood pulp and the fiber’s biodegradability under appropriate conditions. The environmental profile benefits from the closed-loop solvent system, but overall sustainability depends on forest management, energy use, and production practices.