To analyze the feasibility of electrospinning nanofiber yarn using a wrapping yarn forming device, electrospun nanofiber-wrapped yarns and multiscale yarns were prepared by self-made equipment. The relationship between the surface morphology and properties of yarn and its preparation process was studied. The process parameters were adjusted, and it was found that some nanofibers formed Z-twisted yarns, while others showed exposed cores. To analyze the forming mechanism of electrospun nanofiber-wrapped yarn, the concept of winding displacement difference in the twisted yarn core A was introduced. The formation of nanofiber-wrapped structural yarns was discussed using three values of A. The starting point of each twist was the same position when A = 0 with a constant corner angle β. However, the oriented nanofiber broke or was pulled out from the gripping point when it was twisted, and it appeared disordered. The forming process of electrospun nanofiber-wrapped yarn displayed some unique phenomena, including the emission of directional nanofibers during collection, fiber non-continuity, and twist angle non-uniformity. The conclusions of this research have theoretical and practical value to guide the industrial preparation of nanofiber yarns and their wrapped yarns.
Keywords: electrospinning; mechanical properties; mechanism; multiscale yarn; nanofibers yarn.