The Curing Principle of UV Coatings to Influence UVLED Deep Light Curing

The principle of UV coating curing: After UV coating is irradiated by UVLED, the photoinitiator is triggered to produce free radicals or ions. These free radicals or ions crosslink with the double bonds in the prepolymer or unsaturated monomer, forming monomer genes. These monomer genes start a chain reaction to form polymer solid molecules, and a complete curing process ends. Below are several factors that affect its deep solidification.

1、 The impact of UVLED energy

Deep solidification of ultraviolet radiation,

The main condition is that the molecule absorbs light quantum with sufficient energy to become an excited molecule, decomposes into free radicals or ions, and undergoes chemical reactions such as polymerization, grafting, and crosslinking of unsaturated organic compounds, achieving the purpose of curing. The impact of the UVLED energy of the photoinitiator in the supplied UV coating exceeding or insufficient to meet its required energy:

1. Not knowing the UVLED cold light source energy required for photoinitiators, such as blindly excessive supply, not only wastes energy, but also causes negative effects of excessive curing, such as explosion polymerization and reverse curing reactions.

2. When UVLED energy is insufficient, it causes incomplete solidification.

2、 The influence of UV coating thickness

The thickness of UV coating plays a crucial role in the effectiveness of UV curing. If the coating is too thick, the drying time under the same power light source is relatively long. On the one hand, it affects the drying of UV coating, and on the other hand, it can cause the surface temperature of the substrate to be too high, leading to deformation of the substrate; A thin coating can lead to poor surface gloss of the product. In addition, the color scheme, temperature, curing rate, and substrate surface of UV coating coatings need to be adjusted appropriately under different conditions.

3、 The impact of curing distance

UV lamps typically have a distance of around 10-15mm depending on the curing substrate. The curing distance must be adjusted appropriately with the substrate, coating, UVLED lamp irradiation power, etc.

4、 The influence of UV curing speed

Adjust the curing speed of the equipment appropriately based on different substrates, coatings, curing distances, etc. If the curing speed is too fast, the UV coating on the surface of the substrate may become sticky or dry on the surface but not inside; Slow operation speed will cause aging of the substrate surface.

5、 When the viscosity of UV coatings varies greatly due to temperature reasons, the room temperature should be adjusted, generally 15-25 ℃ is more suitable, and attention should be paid to not being exposed to direct sunlight during curing.