Effects of fibrillation and enzymatic defibrillation treatments on mechanical properties of regenerated cellulosit yarns from nmmo process

Abstract

Fibre spinning from a solution of cellulose in N-methyl-morpholine-N-oxidehydrate is an environmentally friendly process (NMMO), which yields cellulose fibres with excellent mechanical properties. A special feature of these fibbers is their ability to fibrillate in the swollen state. It is possible to control and exploit fibrillation of this kind of fibre (generic name: lyocell) through mechanical fibrillation and enzymatic defibrillation treatments. The mechanical properties (elongation at break. Young's modulus, tensile strenght and tenacity) of solvent (NMMO)-spun lyocell yarns samples have been studied in untreated condition as well as after industrial mechanical fibrillation and enzymatic defibrillation treatments. It is observed that the tenacity of lyocell yarn decreases greatly as a result of the treatments, particularly after the enzymatic treatment. For this reason, the control of these operations plays a critical role in ensuring acceptable mechanical properties of the yarns.