Abstract: This paper probed into the subtle differences of chemical dissolving properties of Lyocell fibers and other regenerated cellulose fibers. By investigating the influence of time, temperature and reagent formula on dissolving properties, the classical method — the dissolution method was found out to be suitable for distinguishing Lyocell fibers from other regenerated cellulose fibers and the conditions were optimized.Finally, it determined that the best conditions for the qualitative identification is in a solution of formic acid/zinc chloride (80∶10) at a temperature of 70 ℃ for a time period of 40 minutes.

Key words: Lyocell; regenerated cellulose fiber; qualitative identification; solubility