Performance Nonwovens from Lyocell
By : Aravin Prince Periyasamy & Shrikant R Eklahare
Lyocell is an innovative broad name given to a cellulosic fiber which is produced under an environmentally friendly process by dissolving cellulose in the Tertiary Amine Oxide N-methylmorpholine - N-oxide (NMMO). Lyocell fiber shows some key advantageous characteristics over other cellulosic fibers; for instance, a high dry and wet tenacity and high wet modulus. For the majority of the last century, commercial routes to regenerated cellulose fibers have scoped with the difficulties of making a good cellulose solution by using an easy to dissolve derivative (e.g. xanthane in the case of viscose rayon) or complex (e.g. cuprammonium rayon). For the purpose advanced cellulosic fibers are defined as those made from a process involving direct dissolution of cellulose. The first examples of such fibers have now been generically designed as lyocell fibers to distinguish them from rayon's, and the first commercial lyocell fiber is 'Courtaulds' Tencel.
This article reviews the reasons for the recent growth in the use of lyocell in nonwovens, discussing aspects such as how the key lyocell fiber properties benefit nonwoven producers and consumers, how the processing performance of the fiber has been improved and how to achieve the optimum fabric characteristics from the fiber through spun lacing, needle punching, latex bonding, wet-laying or air laying. Particular reference is made to the benefits of lyocell in hydroentangled wet and dry wipes.