Self-layering behavior of PET fiber deposition in melt-electrospinning process

Melt-electrospinning is an efficient and environmental-friendly technique for producing nano/micro fibers. In this work, the self-layering behavior of poly(ethylene terephthalate)(PET) fiber deposition during melt-electrospinning was investigated based on the electric field simulation analysis by ANSYS and high voltage insulation theory of capacitor for melt-electrospinning configuration. The simulation results demonstrated that during melt-electrospinning process, the electric field strength on the center and lateral surface of the collector changed alternately when some electrically charged jet deposited, making jet depositing location moved around between center and lateral surface, resulted in the formation of the binding fibers separating the inner and outer layers in the deposited PET fiber web. The PET fiber web electrospun in 90 minutes could be laminated freely into thirteen layers. The geometric dimensions of these layers were measured and their morphologies were observed by scanning electron microscopy (SEM). These laminated layers were concentric with almost linearly increasing radius from the inner to the outer. Inner layers featured themselves with appearance of thick center and thin edge, while for outer layers, they presented the appearance of thin center and thick edge. The fibers in the web were quite uniformly and had diameters of about 2 μm.