Tencel :: Sustainable but not necessarily healthy
Tencel® has gained favorable acceptance within the mainstream fashion industry and also in the eco-fashion industry as being a natural fiber that has a flattering drape and is soft, luxurious, breathable, naturally wrinkle-resistant, and environmentally sustainable.
Tencel® is the brand name owned by Lenzing Fiber of Germany for a recently improved fabric from a fiber generically called lyocell. The name “Tencel” has gained popular acceptance but most of the fabrics that are popularly called “Tencel” are actually lyocell. We will use the proper generic name lyocell. Remember that Tencel® is just the brand name for a type of lyocell.
Most people assume that there are two broad categories of fibers: natural fibers like cotton, wool, hemp, ramie and silk; and artificial fibers synthesized out of petrochemicals like nylon and polyester. Lyocell falls somewhere in-between. The raw material for lyocell is cellulose from wood pulp which is broken down chemically in a soupy sludge that is squirted out a showerhead spinnert and reformed as fibers. Lyocell is more accurately described as a recovered or regenerated fiber.
The environmental press has often heralded lyocell as a new fiber that represents a milestone in the development of environmentally sustainable textiles. Lyocell is made from cellulose found in wood pulp which has been harvested from tree farms. Cellulose is the natural polymer that makes up the living cells of all vegetation. The fiber is produced via an advanced 'closed loop' solvent spinning process, with minimal impact on the environment and economical use of energy and water. It often, though not always, uses a non-toxic solvent which is continually recycled during the production process. Production plant emissions into the air from smokestacks and from wastewater are significantly lower in comparison to many other man-made fiber operations.
As with conventionally manufactured cotton fabric, there are many steps and processes involved in taking lyocell from fiber to fabric. The major steps are:
- Creating a solvent solution from wood pulp
- Spinning lyocell fiber from the solvent solution
- Washing lyocell fiber to remove solvents
- Dyeing fiber and producing yarns
- Finishing to produce lyocell fabric
The solvent to digest the wood pulp can be toxic but about 99% is recovered and recycled. Waste products in the air and water from the manufacturing process are minimal and considered harmless. Lyocell fiber is eco-friendly since products made from it can be recycled and lyocell is biodegradable because it is a cellulosic fiber. Products made from lyocell can be recycled, incinerated, or digested in sewage. The fiber will usually degrade completely in just eight days in waste treatment plants.
The process to manufacture lyocell fiber is in fact very nearly a closed loop process in which bleach is not required. Bleach is commonly required in fabric manufacturing, especially for cotton. For this reason, high quality lyocell products contain no free chlorine and are sold as so-called "TCF - products". The European Union awarded this process the Environmental Award 2000 in the category "technology for sustainable developments". Most of the manufacturing facilities that produce lyocell fibers are in the U.S., Europe, and Asia. Processes, including the chemicals that they use, can vary considerably.
While production of lyocell fibers is generally eco-friendly and environmentally sustainable, the transformation of lyocell fibers into fabric and garments can use many or the same harsh, and even toxic, chemicals and processes used in conventional garments. This is because of two properties of lyocell: it doesn’t always accept dyes well, and it has an inherent tendency to fibrillate or “pill”.
Lyocell fiber has a relatively low surface energy, which makes it difficult for dyes to bind to it. Depending upon their ideological leanings, the manufacturing facility might use a variety of chemical processes, enzyme baths, and dye treatments which might, or might not, be eco-friendly.
The manufacturing of lyocell fiber does have significant environmental and ecological benefits. Most of concern about lyocell comes from the sometimes heavy use of chemicals to turn lyocell fiber into garments. Tencel® and lyocell are possibly not appropriate for those with Multiple Chemical Sensitivities. My suggestion for people with chemical sensitivities that are interested in purchasing apparel made from Tencel® and lyocell is to proceed carefully and to shop for lyocell garments manufactured in Europe or the U.S. Sustainable clothing and eco-friendly clothing have great value to the earth but they are not the same as organic clothing.
Enjoy.
Michael
LotusOrganics.com
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