This research proposes a general formula for implementing in the control system of a dry-jet wet spinning machine to achieve a specific diameter size for Polysulfone hollow fibers. By employing Taguchi method, the effect of the operation parameters on the fiber geometry is investigated. The findings emphasize the significance of various fabrication parameters in determining the inner diameter (ID) and outer diameter (OD) of the hollow fibers. To mathematically predict the ID and OD, a first-order equation is developed using the least squares method. The accuracy of the proposed equation is validated through a series of experiments, where the ID and OD of the produced hollow fibers are determined using cross-sectional images by a scanning electron microscope. The results demonstrate a strong agreement between the proposed equation and the experimental data, with a maximum error of less than 7%. This research offers a valuable tool for optimizing hollow-fiber spinning plants and holds promise for improving their overall performance.

The oscillatory diameter of the charged jet during the bubble electrospinning results in beads on the obtained nanofibers. We demonstrate that the applied voltage and the initial flow rate of the jet are the crucial parameters that are necessary to control morphology of the nanofibers. We also find that there is a criterion for production of smooth nanofibers without beads. The theory developed in this paper can be extended to the classical electrospinning and the blown bubble-spinning.

Conducting polymers have been widely investigated for both academic and industrial purposes over two decades. Polyaniline (PANI), a member of the intrinsically conducting polymer family was blended with Nylon 6 in concentrated formic acid. Conducting fibres were spun from the blend solution by wet spinning method. In this process the solvent is replaced by non-solvent and consequently the polymer is precipitated. Qualitative studies were carried out on the effect of coagulation bath. Coagulation bath containing 7.5% w/w Li2SO4 has improved mechanical properties of the fibres. The electrical resistance of fibres containing 5-25% w/w of PANI, varies between 0.665 to 0.015 MΩ.cm-1. It was found that the electrical resistance of fibres depends on their moisture content. Cyclic voltammetric studies were carried out in -350 to 1000 mV vs.Ag/AgCl. These studies showed that PANI/nylon 6 fibres were electroactive. Further more fibre containing 25% w/w of PANI has high electroactivity stability.

Centrifuge spinning is a method that makes possible of fabrication nanofibers rapidly and at high yields.In the centrifugal spinning process, a polymer solution is delivered by the centrifugal force through small nozzle of a rapidly rotating cylindrical drum. Thereby, thinfibers are formed and collected on a collector in the form of a web. In this study, a mathematical model of the dynamics of a viscous liquid jet, which emerges from rotating drum through centrifuge spinning, was derived. The Navier-Stokes equations were solved in this system with the usual viscous free surface boundary conditions. One-dimensional equations were derived using asymptotic methods based upon a slender jet assumption and solved numerically. The effect of angular velocity upon the trajectory, radius, and tangential velocity of the jet was simulated and presented. Increasing angular velocity resulted in a decrease in the size of the liquid jet.Also, increasing angular velocity tended to increase the jet velocity which translated to increase the production rate. The jet centerline became more tightly coiled when the angular velocity increased. In addition, simulated jet diameter was compared with some results reported in our previous work.