1. Irritation of monomer
The active monomer in UV ink has certain irritation and corrosivity to the skin. During the production and use of UV ink, production operators often have skin allergy symptoms due to accidental contact with ink. Therefore, improving the safety of ink, improving the ink production and printing operation environment, and avoiding the physical injury of operators are also issues that the ink manufacturer Foshan Jinyin Ink Industry Co., Ltd. must pay attention to and urgently need to solve.
2. Ink balance performance
Since the acrylate prepolymers and monomers used usually contain highly polar groups such as hydroxyl, carboxyl and amino groups, UV ink has strong affinity for fountain solution and is easy to be emulsified. Secondly, the printing substrate is mainly composed of non absorbent materials such as synthetic paper, gold and silver paperboard and plastic, which has poor absorption of fountain solution. These factors lead to the poor ink balance performance of UV ink in the printing process, and the ink balance is not easy to control, affecting the printability of the ink. Especially when using prepolymers, monomers and additives with high residual hydroxyl value and large polarity, the problem of ink balance performance becomes more and more prominent.
3. Pigment wettability
Compared with traditional offset printing ink, the prepolymer resin system of UV ink has the characteristics of low molecular weight and high polarity. It has poor affinity for the surface of low polarity organic pigment particles, and is difficult to provide good pigment wettability and dispersion stability. The better the wettability, the better the abrasiveness and dispersion. The wettability of pigment directly affects the ink balance, brightness and fluidity, and also affects the occurrence of flocculation in the production process. If the wettability of the pigment is poor, the grinding process must be strengthened, and the operation must be carried out at low temperature to prevent gel.