Influence of aqueous medium on mechanical properties of conventional and new environmentally friendly regenerated cellulose fibers

Comparative investigations between the new lyocell fibers and the regular viscose and modal types were made in order to explain the reasons for the differences in the mechanical properties of the fibers. The purpose was a systematic analysis of structure characteristics and of influence of aqueous medium on the mechanical properties. The properties determined in the wet state reflect the effect of the aqueous medium on the changes in the supermolecular structure during wet treatments [1, 21. The new lyocell fibers consist of longer molecules and have a higher degree of crystallinity. Smaller but longer crystallites are oriented in the fiber axis direction and the voids structure is similar to that of viscose fibers [3]. Good mechanical properties are conditioned by the structure of the lyocell fibers, above all by high values of the orientation factor and crystallinity index. Sorption properties place lyocell fibers between the viscose and modal fibers. The water influence on the mechanical properties of lyocell fibers is considerably smaller compared to the viscose and modal fibers.