UV inks are gradually maturing to market needs

The main components of UV inks include photopolymerization prepolymers, photoinitiators, diluting monomers (reactive monomers), organic pigments, and additives.

Photopolymerization prepolymers are the main components of uV inks, and acrylic resins, acrylic urethanes, epoxy acrylate resins, acrylic polyesters, modified acrylic polyesters and the like are generally used. The photopolymerization prepolymer is a UV ink binder, UV ink adhesion, abrasion resistance, chemical resistance, solvent resistance, and hardness. Viscosity, curing speed, etc. are all determined by it.

The photoinitiator is an active organic group that initiates the cross-linking of the photopolymerization prepolymer. The UV ink curing process is a cross-linking process of the polymer, and the photoinitiator is irradiated with an external light source (generally using a certain wavelength of ultraviolet light). It is excited to become free radicals or ions, and then through intermolecular energy transfer, the prepolymers and photosensitive monomers in the ink form charge transfer complexes. These complexes are continuously cross-linked, so that UV inks generate light. Curing reaction from liquid to solid state. In the course of this reaction, there is substantially no solvent volatilization, which is conducive to environmental protection.

Because UV inks are photosynthetic and cross-linking reactions, the drying speed is fast, the energy consumption is low, and the printed products have good gloss and bright colors. Because the ink film is formed by polymer cross-linking, it is oil-resistant, wear-resistant, water-resistant, and solvent-resistant. It has the advantages of long-term storage and stable performance. There are many types of UV inks, including not only various conventional inks, but also UV ice cream, UV frosting, UV refraction, and UV foam ink.

However, during the printing process, UV inks should pay attention to the skin protection of the operators, otherwise they may be irritated. In addition, the UV light must be prevented from harming the human body and the ozone generated by ultraviolet radiation should be eliminated in time. What's more important is that since the UV inks are cross-linked, they are not easily dissolved and affect the recovery after discarding. The current recycling project is also under study.

According to the latest understanding, combining UV inks with oil inks can form new non-polluting inks without VOCs.