company news about Factors affecting the curing reaction speed of UV adhesive

Factors affecting the curing reaction speed of UV adhesive

  UV glue, also known as ultraviolet-curing adhesive, is a material that uses ultraviolet energy from a UV irradiator to polymerize and harden in a short period of time. UV-curing adhesive is a one-part, solvent-free type, eliminating the environmental pollution associated with solvents. Its curing speed is measured in seconds, making it suitable for mass production and significantly shortening the production process.

  1. Factors Affecting UV Glue Curing 

  a. Curing Speed: Adjust the curing speed of the equipment appropriately based on the substrate, coating, curing interval, etc. If the curing speed is too fast, the UV glue on the substrate surface may become sticky or dry on the surface but not on the inside; if the curing speed is too slow, the substrate surface may age.

  b. UV Glue Coating
  The thickness of the UV glue coating plays a crucial role in UV curing. A thick coating will result in a longer curing time under the same wattage light source. This will not only affect the UV glue's curing process but also cause the substrate's surface temperature to be too high, resulting in a poor product gloss. In reality, the UV glue's curing rate, final cure depth, and surface drying performance are all dependent on factors such as the UV light source, exposure time, and the material's light transmittance. It is recommended to determine the specific curing time through experimentation.

  2. How to promote the curing speed of UV glue

  c. UV LED Curing Energy

  The UV light energy must be moderate—neither excessive nor insufficient. Addressing this requirement will ensure UV glue curing speed. During the curing process, the UV light energy supplied to the photoinitiator in UV glue often exceeds or falls short of its required energy. For example, if the UV light energy required by the photoinitiator is known, supplying a scientifically and rationally greater amount of energy to ensure thorough curing is normal. However, blindly supplying an excessive amount of UV light without knowing the required energy not only wastes energy but can also cause negative curing effects, such as implosion and reverse curing reactions. Insufficient UV light energy can easily result in incomplete curing.

  d. Working Environment

  UV glue's viscosity changes significantly with temperature, so the room temperature should be adjusted accordingly. 15-25°C is generally suitable. Also, be careful not to expose the glue to direct sunlight during application.

  e. UV Curing
The distance between the UV LED and the surface of the object being illuminated also affects the curing speed. The distance will vary slightly depending on the substrate being cured. If the distance is too low, the UV lamp surface will be very hot, causing the substrate to deform. If the distance is too high, the UV energy will be low, and the substrate surface will not dry out and become sticky. The curing distance must be adjusted appropriately based on the substrate, coating, and lamp power.