What are the factors affecting the deep curing of UVLED?

What are the factors affecting the deep curing of UVLED? As a kind of curing equipment, UVLE light curing machine has many advantages compared with traditional UV mercury lamp, such as fast curing speed, convenient operation, no need to replace lamp tube, environmental protection and safety, cold light source, etc. Its curing principle is that UV glue is initiated by photoinitiator after irradiation by UVLED, which produces free radicals or ions. The double bonds of prepolymer or unsaturated monomer cross-link to form monomer genes. These monomer genes begin the chain reaction to form polymer solid ionomers, which is a complete curing process. Today, Yuntong Technologies wants to share with you several factors that affect the deep UV curing of UVLED.

 

Several influencing factors of UV-LED deep photo-curing:

 

I. The influence of UV LED energy

 

 

 

The main condition of deep curing of ultraviolet radiation is that molecules must absorb enough energy of light quantum to become exciting molecules, decompose into free radicals or ions, so that unsaturated organic compounds can be polymerized, grafted, cross-linked and other chemical reactions to achieve the purpose of curing. Among them, the UV LED energy supplied by photoinitiator in UV glue exceeds or falls short of its required energy.

 

 

 

1. Unaware of the need of photoinitiator for UVLED cold light source energy, such as blindly excessive supply, this practice not only wastes energy, but also causes negative effects of excessive curing, such as explosion polymerization, anti-curing reaction, etc.

 

 

 

2. When the energy of the UV LED is insufficient, the energy of the UV LED must be moderate, that is, it can not be excessive or insufficient, so as not to cause complete curing.

 

II. THE EFFECT OF THICKNESS OF UV COATINGS

 

 

 

The thickness of UV coating plays a key role in the effect of UV curing. The coating is too thick and the drying time is relatively long under the irradiation of the same power source. On the one hand, it affects the drying of UV coating, on the other hand, it will cause the surface temperature of the substrate to be too high, which will lead to the deformation of the substrate; on the other hand, the coating is too thin, which will lead to the poor gloss of the product surface. In addition, the color, temperature, curing speed and substrate surface of the thick and thin UV coatings need to be properly adjusted under different conditions.

 

 

 

3. Effect of Curing Distance

 

 

 

Ultraviolet lamp according to the different curing substrates, the general distance is about 10-15 mm. The curing distance must be adjusted appropriately with the irradiation power of substrate, coating and UV LED lamp.

 

 

 

IV. EFFECT OF UV CURING RATE

 

 

 

According to the different base material, coating and curing distance, the curing speed of the equipment should be adjusted appropriately. The curing speed is too fast. The UV coating on the surface of the base material sticks or the surface is dry and does not work inside. The running speed is slow and the surface of the base material will be ageing.

 

 

 

5. The Impact of Working Environment

 

 

 

When the viscosity of UV coatings varies greatly due to temperature, room temperature should be adjusted. Generally, 15-25 C is suitable, and attention should be paid to curing without direct sunlight.