Introduction to Fluorescent Dyes and Fluorescent Fabrics

Introduction to Fluorescent Dyes and Fluorescent Fabrics
Release time: March 23, 2018 Number of reads: 1079
A dye that can strongly absorb and emit fluorescence within the visible light range.
Fluorescent dyes for textiles:
1. Fluorescent whitening agent
2. Disperse fluorescent dyes
3. Fluorescent coating
Fluorescence generation principle
Fluorescence is a phenomenon of photoluminescence. When ultraviolet light, or some type of light, shines on a fluorescent substance, the substance absorbs energy consistent with its characteristic frequency, transitioning from the ground state to the excited state with higher energy.
Molecules in unstable excited states will transfer and relax to the lowest vibrational level of the excited state in a short period of time, balance the excited state, and then fall back to the higher vibrational level of the ground state from there. During the descent process, energy is attenuated in the form of fluorescence, and the fluorescence disappears immediately upon cessation of irradiation.
Fluorescent whitening agent
Whitening agents have been widely used in textiles, papermaking, laundry detergent, soap, rubber, plastics, pigments, and paints.
Disperse fluorescent dyes
Disperse fluorescent dyes have small molecules and no water-soluble groups in their structure. With the help of dispersants, they are uniformly dispersed in the dye solution and enter the interior of the fibers. After soaking in the dye solution, it is immediately dried and then subjected to hot melt treatment. Under the action of high temperature, dyes deposited on the fabric can diffuse into the interior of the fiber in a single molecule form, completing the dyeing of chemical fibers in a very short time.
Due to the fusion of small molecules of fluorescent dyes with fibers, the fabric has good color fastness to rubbing and washing, but poor color fastness to light
Fluorescent coating
1. Fluorescent coatings are slurries composed of fluorescent pigments, dispersants, and wetting agents, which are insoluble in water and have no affinity for fibers. They cannot be dyed under conventional dyeing conditions
2. If the fluorescent pigment particles are large, the coloring rate is low, the color light is dim, the fastness is poor, and the color light is not easy to be accurate; If the particles are small, the coloring rate is high and the fastness is good, but the brightness has an impact.
3. Fluorescent coatings are attached to the surface of fibers through immersion rolling, and then the resin component of the adhesive helps the coating to fix on the surface of fibers, achieving a certain degree of color fastness. Due to the influence of the resin contained in the adhesive, the texture of the fabric will become harder.