How to determine the curing time of UV adhesive appropriately
2021-06-15 979
To determine the appropriate curing time for a UV adhesive, an important tool is first needed, which is a radiometer.
A radiometer can determine how much light intensity is present at the adhesive layer. The different methods depend on how you use the adhesive. If adhesive is used between two substrates, the thickness of the adhesive layer is usually 0.05-0.1mm. Generally, when the light intensity is greater than 500mw/cm2, the curing time for this type of adhesive method is usually 2-5s.
Each adhesive should indicate its required curing energy on the TDS, and the curing time under this light intensity should generally be less than 5 seconds. If a deeper part is sealed, the curing depth is important.
The curing energy or curing time described by TDS can generally only be used as a reference, and the most important thing is to personally test it. This is the best way to calculate the correct curing time, whether it is to check the holding time, curing depth, or surface drying time. The minimum light intensity set on the adhesive layer can be 50 mW/cm2. By increasing the distance of the lamp, it can be achieved until the light intensity measured by the radiometer is 50 mW/cm2. Starting from a high light intensity, there is room for variation in both light intensity and time when processing components, which can control the machining process.
After setting a fixed light intensity, cure the adhesive at different times. You can see that the tensile strength, compressive strength, surface drying time, curing depth, hardness, or other data points will climb to a maximum value and then enter a stable period. Once the starting point of the stability period is determined and a safety range is added, there is a basic process. It is also possible to set the time to remain unchanged, change the light intensity, and then use the same dose data points. By understanding the maximum and minimum light intensities and the time required to cure the adhesive, the process can be determined.