A study of rheological limitations in rotary jet spinning of polymer nanofibers through modeling and experimentation

Abstract

The recently popularized method of rotary jet spinning (RJS) or centrifugal spinning is investigated to evaluate the rheological limitations of polymer solutions and melts to optimal spinnability. The influence of Newtonian or non-Newtonian behavior of the polymer on spinnability is discussed. We observe that highly viscous polymers tend to block the die channels within a rotary jet spinneret and therefore suggest the use of relatively low Newtonian viscosities of between 1 and 10 Pa s for optimal fiber production. Computational fluid dynamics simulations are used in conjunction with experimental data to establish important processing parameters, such as typical shear rates in the device and optimal polymer melt or solution viscosities. A theoretical model for RJS is compared to measured fiber diameters. The comparison shows that although fiber diameters can be estimated very roughly in the case of polymer solutions, the prediction of fiber diameter in the case of polymer melts require further modeling work.

High-modulus rotary jet spun co-polyimide nanofibers and their composites

“…The rheological properties of the solutions were tested to confirm their spinnability, which through experimentation has been evaluated to require shear viscosities between 1 and 12 Pa s when using 30 Ga needles [3]. A viscosity higher than 12 Pa s (PI003) adversely affected the ability of the fluid to flow through the needles to form a fiber, whereas viscosities significantly below 1 Pa s (PI002) resulted in beaded discontinuous fibers being formed due to insufficient chain entanglement and increased solvent evaporation time.…”

“…During the RJS process (Figure 1), pressure is build up in a spinning vessel containing orifices, which is generated by both centrifugal force and hydrostatic pressure. The ejected polymer is subsequently subjected to an elongational flow to produce an ultra-thin fiber [3], which is collected at a set distance using one of multiple collection methods.…”

Review of the Principles, Devices, Parameters, and Applications for Centrifugal Electrospinning

“…This research result has a significant reference function for centrifugal electrospinning. [123] The viscosity of the polymer solution also has a significant influence on the centrifugal electrospinning process because the solution viscosity is closely related to the polymer concentration.…”

Design of the Prototype of Contact Drawing Device for Potential Individual Therapeutic Fiber Formation Purposes

“…All polymers with physicochemical properties suitable for rotary-spun microfibers can form contact fibers as well [9]. Of the pharmaceutical polymer excipients, the PVP 30 should be highlighted [10]. The prototype was also tested with PVP 30 polymer.…”