Introduction of UV curing ink
Date: 2020-07-25 / Source: Zhongkai Packaging / Views: 976
The UV-curable jewelry packaging card ink is an ink that can undergo a cross-linking reaction under the irradiation of ultraviolet (UltraViolet) light waves and can instantly change from liquid to solid, so it is also called "UV" ink. Its main components include photopolymerizable prepolymers, optically sensitive monomers, organic pigments, photopolymerization initiators, and additives. Among them, the photopolymerization initiator is the most important component in the UV ink, and is the beginning of the photopolymerization reaction. Commonly used photopolymerization initiators include aromatic ketones. UV UV curing ink curing/drying principle The main reason for UV ink curing is due to the action of ultraviolet rays. Under UV irradiation, the photopolymerization initiator in UV ink absorbs photons of a certain wavelength and turns into free molecules, which become free radicals. Then, through the transfer of energy between molecules, the polymerizable prepolymer and the optically active monomer are turned into an excited state, and a charge transfer complex is generated, and the complex is continuously cross-linked and polymerized, and cured to form a film.
The curing process of UV ink is a process of photochemical reaction, that is, under the action of ultraviolet energy, the prepolymer is cured into a film in a very short time. In addition to causing the surface of the ink to cure, ultraviolet light can penetrate deep into liquid ultraviolet curing In the ink, and stimulate the further curing of the deep ink film. In traditional inks, oil-based inks are solidified by oxidation, while solvent or water-based inks are mainly solidified by the evaporation of water or solvents, and some inks can penetrate into the paper. Therefore, compared with traditional inks, the polymerization and drying of UV-curable inks is more thorough, without any evaporation or solvent-based contaminants, and the ink film is 100% cured.