Four methods to determine if UV ink is completely cured after UV lamp irradiation: 1. Pencil hardness test All UV ink technical conditions include pencil hardness. According to this requirement, we can use a pencil hardness tester. If the requirement is met (generally 3-4H), it proves that the ink is completely cured. 2. Solvent dripping method test As mentioned above, the technical conditions of UV ink also include solvent resistance. Because after the ink is completely cured, the internal molecular structure will change, converting to double bonds. The higher the conversion, the more complete the curing, and the overall shape of the ink will change accordingly.
Four methods to determine if UV ink is completely cured by UV lamp irradiation:
1. Pencil hardness test
All technical conditions for using UV inks include pencil hardness. According to this requirement, we can use a pencil hardness tester. If the requirement is met (generally 3-4H), it proves that the ink has been completely cured.
2. Solvent dripping method test
As mentioned above, the technical conditions of UV inks also include solvent resistance. Because after the ink is completely cured, the internal molecular structure will change, converting to double bonds. Higher curing means complete conversion, and the ink forms a tight coating layer. According to the solvent resistance, drop propionic acid solution on the surface for 2 minutes. If there is no change, it proves that the ink has been completely cured after UV lamp irradiation.
3. Pressure test
This method originates from the detection method of coatings. Select a 500g weight with a flat bottom surface, place a few cotton fibers on the UV-cured surface, then press the weight on the cotton fibers for 2-3 minutes, and then remove the weight. If the cotton fibers do not stick to the surface, it proves that the surface is completely cured.
4. Visual observation method
Completely cured UV ink has a bright surface and no fuzzy phenomenon, and there is no shadow at the edges. This is also one of the important characteristics to determine whether the ink is completely cured by UV lamp irradiation.
Of course, a lot of experience gained in long-term production through the comprehensive application results of UV ink performance, working environment, working conditions, and equipment performance is valuable technical wealth. Combining daily experience with test results to determine whether it is completely cured will be more accurate.
