Design and Performance of a Novel Scalable Core–Sheath Inverted Nozzle Soft Material Pressure Spinner

Core-sheathed inverted nozzle pressurized gyration (CsINPG) is a novel fiber manufacturing process based on gas blowing-assisted rotary coaxial spinning technology, capable of large-scale manufacture of core-sheathed, micropolymeric structures. The CsINPG spinning vessel is constructed from polycarbonate and has a unique nozzle arrangement, which increases uniformity and facilitates the formation of core-sheathed fibers. The CsINPG apparatus functions as a jet generator, ejecting the spinning feedstock under the combined forces of centrifugal force and pressure differentials. The centrifugal force, which is generated by the spinning of the vessel, is powered by a connected electrical motor. This enables the loaded polymeric feedstock to overcome its surface tension, facilitating fluid ejection through the external nozzles on the vessel wall to form spinning jets. These polymeric jets undergo further stretching through the assimilation of the pressure differential, which is powered by introducing nitrogen flows. This further increases the initial velocity and acceleration. In core-sheathed pressurized gyration, the feedstock is present in two different chambers of the core and the sheath. Furthermore, during "inverted" nozzle-pressurized gyration, the entire manufacturing process is carried out on a horizontal axis, facilitating the controlled streaming of these spinning jets into a water bath. This facilitates the usage of "green polymers" such as alginate and cellulose, which require water baths to be converted from soluble streams to insoluble fibrous structures. These fabricated core-sheathed fibers, manufactured under the optimum parameters in this study, produced fibers with average diameters measuring <10 μm. This paper will delve into the development of the novel CsINPG manufacturing process, focusing on the design of the spinning vessel, the parameters used, the optimization of parameters and their consequences, and the potential future applications of the manufactured core-sheathed fibers.