Production of Parallel Aligned Nanofiber Rovings From Continuous Bundles

Abstract This study presents a novel approach to converting electrospun polyacrylonitrile (PAN) nanofiber bundles into rovings, essential for nanofiber yarn spinning, through the implementation of false twisting and drawing processes. The false twisting process is optimized by varying the input bundle angle (40° to 60°), twister type (A, B, C), and rotation speed (20, 50, and 80 rpm). A bundle input angle of 55°, twister type B, and a twister rotation speed of 80 rpm show the best results in terms of longer twisted length, lower average thickness, and thickness variation values. The morphological, physical, and mechanical properties of the resulting nanofiber rovings for drawing process implementation are also evaluated. Scanning electron microscope (SEM) analysis further reveals significant improvements in nanofiber alignment and uniformity. The drawing process reduces the average nanofiber diameter from 297 to 200 nm and decreases the standard deviation of alignment angles from 14.2° to 8.1°, indicating a substantial enhancement in parallel nanofiber alignment. These morphological changes contribute to a marked increase in tensile strength from 2.2 to 3.3 cN tex⁻¹. Integrating false twisting and drawing processes in electrospun nanofiber production can significantly enhance the mechanical properties and alignment of nanofibers, making them more suitable for advanced textile applications.