Dual-wavelength fluorescent anti-counterfeiting fibers with skin-core structure

Abstract

AbstractIn this work, a skin-core structure was designed, and three kinds of dual-wavelength fluorescent anti-counterfeiting (DWFA) fibers, including UV short-wavelength/UV long-wavelength, infrared/UV short-wavelength, and infrared/UV long-wavelength excitable DWFA fibers with skin-core structure, were spun using fluorescent powder/PP pellets as the skin material and pure PP as the core material. The results showed that these DWFA fibers emitted two different colors of light under excitation of two different wavelength lights, which exhibited higher anti-counterfeiting safety. Take UV short-wavelength/UV long-wavelength DWFA fibers, for example; the influence of skin-core ratio on the structure and properties of fibers were investigated, and then the luminous efficiency of DWFA fibers with skin-core structure and homogenous structure was compared. The microscope photos and 3D simulation of fluorescent powder in fibers by confocal laser scanning microscope showed that the fluorescent powders were basically distributed in the skin layer of fibers. The crystallinity degree and tensile strength of DWFA fibers with skin-core structure decreased first and then increased with the decrease in skin-core ratio, whereas elongation of fibers showed an increasing trend. Compared with homogenous DWFA fibers, the skin-core DWFA fibers exhibited higher luminous efficiency under the same fluorescent powder content.