Influence of intensified cellulose dissolution process on spinning and properties of lyocell fibres

Abstract

Effect of intensification of cellulose dissolution process on the spinning of lyocell fibers and their physical properties was systematically investigated. The cellulose dissolution process was intensified by pre-swelling of the pulps that benefited in bringing down the conventional process temperature of 75 °C to 50 °C as well as by assisting in good dissolution and formation of homogeneous dope. Further, effect of dopes prepared from pre-swelled and un-swelled pulps at a lower temperature (i.e. 50 °C) on spinnability and fiber properties, was thoroughly investigated and compared with dopes prepared at 75 °C. The resultant fibers were morphologically and structurally analyzed using SEM and XRD and correlated with their physical properties. It was observed that fibers regenerated from pre-swelled dope, showed increased overall molecular orientation (measured by birefringence) as well as high amorphous orientation that resulted in improved tenacity of the fibers. Finally, it has been observed that cellulose dissolution using pre-swelled method is an energy-efficient technique over un-swelled method (almost 35% at 50 °C and ∼20% at 75 °C of energy saving). Present work makes lyocell process more sustainable and simultaneously enhance fiber properties.