Probability of jet roping in solution blowing of multiple jets

Abstract

This study describes the development and implementation of a lab‐scale four‐needle nosepiece for solution blowing, which enabled the investigation of the roping probability of four polymer jets at different inter‐needle distances and air velocities. The roping probabilities of the four jets were compared to the corresponding roping probabilities of two jets previously established by the present group. The comparison revealed that at the relatively low air velocities (pressures), the four‐jet configuration reduces roping relative to the two‐jet case, which stems from the reduction of the end effect. However, at relatively high air velocities (pressures), turbulent pulsations in the surrounding air become more dominant than the end effect. Accordingly, the four‐jet case reveals a higher probability of roping at higher air velocities (pressures). The findings shed light on the behavior of multiple solution‐blown jets and the impact of the end effect on roping. The severity of roping in the case of four jets at diminishing inter‐needle distances and increasing air velocity was analyzed using recordings of polymer jets in flight by a high‐speed camera and scanning electron microscopy of the corresponding laydown structure.

Fabrication of stretchable and high‐filtration performance melt‐blown nonwoven webs for PM0.3 aerosol filtration

“…However, it is worth mentioning that all PP and PP‐TPU nonwoven samples exhibit fiber‐fiber soldering (i.e., fiber bundles) defects. These fiber‐fiber soldering points noticed within the PP and PP‐TPU nonwoven webs attributed to the process of surface tension‐driven, as elucidated by Balakrishnan et al 21 Another study explored the likelihood of achieving fiber‐fiber soldering being greater as a result of increased air turbulence primarily caused by elevated air pressure 22 . Helically shaped fibers were observed for TPU blended melt‐blown PP filter webs (PP‐TPU) as indicated in Figure 3b,c.…”

“…These fiber-fiber soldering points noticed within the PP and PP-TPU nonwoven webs attributed to the process of surface tension-driven, as elucidated by Balakrishnan et al 21 Another study explored the likelihood of achieving fiber-fiber soldering being greater as a result of increased air turbulence primarily caused by elevated air pressure. 22 Helically shaped fibers were observed for TPU blended melt-blown PP filter webs (PP-TPU) as indicated in Figure 3b,c. These helical fibers are spiral-shaped structures that have great resemblance with the helical coil of springs.…”

Electromagnetic shielding Janus membrane for direct current‐type pressure and sliding sensing

“…The obtained PAN/Fe 3 O 4 fibers (Figure 1b ) rope with each other to form a fibrous membrane, and the morphology and diameter of fibers can be tunable by adjusting electrospinning parameters 26,27 . The procedure of ANI in situ polymerization onto PAN/Fe 3 O 4 fiber membrane was carried out as follows.…”

“…Flexible textile‐based electronics have garnered significant attention for their remarkable attributes, including favorable flexibility, stretchability, lightweight, and suitability for wearable applications. The fibrous structure of these textiles can be finely tuned by adjusting the operational parameters during the fabrication process, 26–28 making them highly desirable for the development of next‐generation wearable EMI shielding materials 14,29 . The Janus structure characterized by distinct properties on each side, provides a viable approach for constructing multifunctional electronics 30–32 .…”