Lyocell is the generic name for a biodegradable fabric that's made out of treated wood pulp. It's commonly sold under the brand name Tencel®, which is made by Lenzing AG. Known for its versatility, durability, and strength when both wet and dry, this material is used in everything from clothing to cars. Though it's often seen as eco-friendly because of its natural origins and its manufacturing process, it is made with petrochemical derivatives, and takes a lot of energy to produce.
The production process for lyocell begins by treating wood chips approximately the size of a coin until they form a substance similar to a thick paper, which is then sent to a fabric production factory. Once there, it is broken down into about 1 inch (2.5 cm) squares and chemically dissolved. The resulting slurry is then forced through a device called a spinneret, which has many small holes in it, somewhat like a strainer. This causes the mixture to form long fibers, which are chemically treated again, rinsed and dried, and lubricated before being compressed, combed, and cut. After this, they can be spun into yarn for use, either alone or in combination with other materials.
Characteristics and Uses
In its pure form, this material is very strong both when wet and dry, and lasts a long time. It can be mixed with many other types of fibers, including cotton, wool, linen, silk, and Lycra®; and can also be treated to have a variety of textures, from silky to denim-feel. It drapes well and resists wrinkles, which makes it popular for dress clothing. Additionally, it's very absorbent and wicks moisture well, and so is often used to make athletic clothing and summer garments. Depending on how it's treated, lyocell can be either machine washed, hand washed, or dry clean only.
Besides clothing, lyocell is used in making linens, some cigarette filters, vehicle carpeting, baby wipes, and bandages. Its durability makes it well-suited for industrial uses too: it's commonly found in conveyor belts, oil filters, and capacitor separators. It is also used to reinforce some plastics and in making some types of paper.
Debate over Eco-Friendly Status
Lyocell is often seen as an environmentally friendly fabric since it comes from renewable sources, is biodegradable, and is made in a closed-loop system that recycles almost all of the chemicals used. The raw materials needed to make it also take up much less land and water than those needed for comparable materials like cotton. Additionally, Tencel® is usually made with eucalyptus trees that are grown without pesticides or artificial irrigation. While the trees are a sustainable resource, the wood does have to be shipped to manufacturing plants from Africa, which takes a lot of fuel. The production process also takes a lot of energy, and the substances used to treat the fibers are derived from petrochemicals. The processes used to dye or texture lyocell sometimes include the use of toxic chemicals, though this varies from producer to producer.