The preparation of polypropylene microfiber yarns via vortex airflow-assisted melt differential electrospinning

Polypropylene (PP) yarn possesses the advantages of low density and exceptional mechanical properties. Through electrospinning, fibers of PP yarns can be refined from 10 to 20 mu m to an ultrafine level, thereby acquiring an enlarged specific surface area and more functional sites, expanding its application in high-value areas. Herein, vortex airflow-assisted polymer melt differential electrospinning was proposed to fabricate PP microfiber yarns. Under the influence of an electrostatic field, molten PP automatically splits into multiple jets that are further stretched and cooled into ultrafine fibers by suction airflow induced by vortex airflow. Subsequently, multiple ultrafine fibers were twisted into PP yarns using the vortex airflow. The effects of voltage, melt feed speed, and air pressure on the PP electrospun yams formation process as well as the morphology and mechanical properties of both the yarn and fibers were investigated. The results showed that the diameter of PP fibers ranged from 3 to 5 mu m. The PP microfiber yams exhibited a relatively high mechanical strength of 1.6 cN/tex under conditions of 56 kV voltage, 0.22 g/min feed rate, and 0.3 MPa air pressure. Finally, the woven fabric made from electrospun PP yams demonstrated higher hydrophobicity compared with fabric woven from commercial PP filaments, suggesting potential applications in waterproof fabrics.