Lyocell Fiber Resolves Environmental Issue with Viscose Rayon


Recently, patent applications related to Lyocell fiber are on the rise. This product is a regenerated cellulose but also an environment-friendly fiber that does not cause pollution.

Viscose rayon, one of the existing regenerated cellulose fibers, uses pulp as raw material. Carbon disulfide, which is used to melt pulp, enters the human body through respiration and damages nerves, causing complications like dull pain in the feet and hands or amblyopia (eyesight decline), and also incurs serious environmental pollution, including strong odor. Consequently, related facilities have been on the decline in advanced countries. Korea's only viscose fiber producer, Wonjin Rayon, also closed its factory in 1993.


However, as regenerated cellulose fibers have excellent absorptiveness as natural fibers and also a pleasing feel, demand has been steady. Since the early 1990s, respective nations have continued research on new regenerated cellulose fibers that do not cause environmental problems. As a result, Lyocell fibers were successfully developed in Germany and the U.K in 1993 and in Korea in 1997.

With high moisture absorption like cotton and a refreshing feel, as well as two to threefold improved strength, a previous disadvantage, Lyocell fibers are now widely used to manufacture high-quality jackets, blue jeans, tent cloth, etc.


Lyocell fibers are made by dissolving crushed pulp with a solvent, N-Methylmolphorine-N-Oxide (NMMO), into a gel state and by spinning the dissolved pulp in a mixed solution of NMMO (15%) and water (85%) and then allowed to coagulate. Since all of the used NMMO solvent is recovered, no pollution is generated. It is a very high technology solution involving a simpler manufacturing process and shorter manufacturing period compared with viscous fibers.

Patent applications related to Lyocell fibers totaled 96 over the past 10 years (1994-2003). Of these, 62 applications filed since 2000 accounted for 65% of the total, showing a recent sharp increase.

In terms of nationality, applications by Koreans numbered 49, or 51% of the total. Until the middle of the 1990s, meanwhile, those by foreigners accounted for the majority, but entering the 2000s, the proportion of Korean applications significantly increased. This trend implies that technology development for Lyocell fibers by domestic synthetic textile firms is becoming more active.

By technology field, patent applications for raw yarn manufacturing processes such as spinning speed and spinning temperature to manufacture Lyocell fibers led all others at 41 (43%) followed by those for Lyocell fabrics, etc. with 29 (30%), those for spinning solutions, including addition of polyvinylalcohol to prevent cracking on Lyocell fiber surfaces, with 26 (27%). In the spinning solution field, in particular, applications by Koreans surpassed those of foreigners remarkably. This indicates that Korean synthetic textile firms are making concentrated efforts for quality enhancement of Lyocell fibers.


Domestic synthetic textiles firms also are developing high-strength Lyocell fibers similar to high-strength nylon. If these efforts are successful, Lyocell fibers are expected to contribute significantly to the development of Korea's industrial textile raw material industry, tire cords, belts, etc.