Screen printing, UV ink due to high efficiency, no pollution and other outstanding advantages, its application has become more and more widely, and will become a trend, when it comes to how to determine whether the ink is fully cured, many people believe that in the cured ink surface Nail scraping knows. But because each person's hand strength is not the same, the way and angle of force are also different; nail file does not have a recognized standard, so this method is not scientific, there are many varieties of UV ink, the scope of application of different and thickness differences rely only on It is not possible to determine if the hand is completely cured. After several trials, the following methods are available for reference:
1. Pencil hardness test
The technical condition of all UV inks has the content of pencil hardness. According to this requirement, we can test with a pencil hardness tester. If it meets the requirement (usually 3 to 4 hours), the ink has been fully cured.
2. Test with drop solvent
As mentioned above, the technical conditions of UV inks also have resistance to solvents. According to the performance of solvent resistance, the propionic acid solution is dripped on the board surface for 2 minutes, and if no change is confirmed, it is completely cured. Because the ink completely cures, the internal molecular structure changes, and the double bonds are converted, and the conversion is completely cured. As a result, the ink as a whole forms a tight coating layer.
3. Pressure test
This method is based on the paint detection method. Choose a 500g weight with a smooth bottom, put several cotton fibers on the UV-cured surface, and then press the weight on the cotton fiber for 2 to 3 minutes, then remove the weight, if the cotton fiber does not stick to the surface The surface is fully cured.
4. Appearance observation method
Fully cured UV inks have a shiny surface and are free of gross defects, with no imaginary edges. This is one of the important features in determining the complete cure of the ink.
Of course, many of the experience gained through the synthesis and application of UV inks in terms of performance, work environment, working conditions, and equipment performance during long-term production is a valuable technological asset. However, today's technology continues to evolve and how to make valuable The combination of experience and scientific actual combat will become the development direction of the industry. It is more accurate to determine whether or not to completely cure by combining the usual experience and testing.