Wearable Colorful Nanofiber of Thermoplastic Polyurethane (TPU) Mechanical and Colorfastness Properties by Dope Dyeing

Abstract

Colorful nanofiber membranes applied to wearable textiles and products with the direct waterless dope dyeing method are gaining a lot of interest in the research area. However, the challenge remains to produce it with a less chemical and easier process. The study analyzed the mechanical strength and colorimetric properties of thermoplastic polyurethane (TPU) colorful nanofibers by varying the electrospinning machine parameters and variables. TPU and dye content were implemented within the specified range of 0.015–0.035 wt% and 0.0015–0.0045 wt% accordingly. The electrospinning parameters were varied at the distance of 5–20 cm, the fiber collection drum was fixed at 250 RPM, the feed rate was constant at 1–2 mL/h, and the applied voltage was not fixed; it was adjusted by understanding the solution viscosity, temperature, and humidity. The voltage range was 12–22 kV. The TPU 0.25 wt% sample showed smooth and less bead morphology and the colorfastness to wash, rub, perspiration, light, and laundry result showed excellence for most of the samples, and the mechanical strength was up to 9.8 MPa, which was acceptable for commercial decorative applications compared to pure TPU. Two printing techniques were utilized: pigment print, which is a flat-screen 1D print, and high-density pigment print, which is a kind of 3D printing. It will enhance the aesthetic appearance of the membrane. This printed membrane was stitched into t-shirts and fashion accessories. The first aim was to make colorful nanofiber using the dope dyeing method in an electrospinning machine; the second purpose was to apply 1D and 3D printing to the colorful nanofiber membrane; and the third objective was to sew the printed colorful nanofiber into commercial apparel and accessories for the common consumer. This work may open a new path for nanofiber colorful dyeing with low cost and energy resources, and it may promote waterless dyeing for wearable printed textiles, decorative products, and accessories.