A Novel method for Producing an Open end Yarn from PAN Electrospun Nanofibers

Electrospinning is the most versatile method for producing continuous fibers with a nanometer diameter up to submicron diameter, which was first introduced in 1934 [1]. In a typical process, a high voltage is applied to the solution, which is extruded from a spinneret to form a droplet. At a critical voltage, above 5kV, the electrostatic repulsive force within the solution will overcome the surface tension and cause a fine jet of solution to erupt from the tip of the pendent drop and subsequently accelerate towards a grounded collector, which is charged with a different potential. As the jet travels through the air, the solvent evaporates and the chaotic nature of the electrospinning jet motion, or bending instability, cause the jet to be stretched many times to its original length to produce a random oriented of continuous, ultrafine fibers of the polymer in the form of nonwoven mats on the grounded target [2]. Nonwoven fibrous mesh is suitable merely for some purposes such as filters, wound dressings and tissue scaffolds [3]. Meanwhile, obtaining continuous aligned nanofibers as a yarn is very important for many areas such as textile products, medical applications, surgery yarns and tissue engineering. Although a few techniques have been developed to align electrospun nanofibers [4,5], further improvements are required to collect the fibers as a yarn for practical applications. In the present paper, a novel technique is described to manufacture yarn consisting of aligned electrospun nanofibers with infinite length, a widespread range of linear density and over large collector area by using a liquid substrate and modifying the electrostatic field in a simple configuration