UV Ink Adhesion Problem and Solutions During Printing：
What are the reasons for the incomplete curing of UV ink and the sticky surface?
1. The lamp is aging.
The flexographic UV ink absorbs ultraviolet light with a wavelength of 200-400nm, and the general power must be greater than 150W/cm to be completely cured. The medium pressure mercury lamp currently used has an average service life of 500 to 100 hours. As the electrode gradually decomposes, the inner wall of the lamp tube produces deposits, and the transparency and ultraviolet light transmittance are gradually weakened. Therefore, the lamp tube should be regularly tested. Check and replace the lamp in time.
It is strongly recommended to use a new type of UVLED lamp to replace the mercury lamp. The UVLED lamp produced by YANSO can save 60-80% of electricity costs, extend the life span by more than 20 times, and have low irradiation temperature. Don't worry about the object being damaged. , Which can satisfy any uv industry use. UVLED curing lamp adopts compressor refrigeration water circulation cooling system, automatic water shortage, overheating and overload intelligent protection system, can adjust the size of ultraviolet energy power, and can set and control the switching time arbitrarily. There are various UV wavelengths such as 260-280nm, 365-370nm, 380-385nm, 395-410nm, etc. for your choice! UVLED lamp is the best choice for modern UV industry.
2. The power of the light source is not enough.
Fast printing speed is also the cause of incomplete curing of UV ink and sticky surface. At this time, the printing speed can be reduced or the light source power can be increased.
3. The curing speed of UV ink itself is slow.
Can add light curing accelerator, reduce printing speed or find ink supplier to solve.
4. Excessive ethanol.
Some manufacturers use ethanol to dilute UV inks, and excessive ethanol will affect the degree of light curing, resulting in incomplete light curing and sticky surface. Therefore, try to avoid using ethanol to dilute. If you need to reduce the viscosity of the ink, you can use UV ink thinner.
When printing PE, BOPP, PET and other films with UV ink, why does the adhesion phenomenon appear unsatisfactory and how to solve it?
1. The degree of corona treatment on the film surface is insufficient. Generally, the surface tension must reach 3.8x10N-2/m or more in order to obtain good adhesion of the ink.
2. The UV ink is not cured enough. Therefore, the UV ink must be completely cured.
3. UV ink shrinkage greatly affects adhesion. Adding a certain amount of monofunctional reactive diluent or a small amount of filler can improve adhesion. In addition, the addition of UV ink adhesion promoter can improve the physical adsorption of UV ink and substrate, thereby improving adhesion.
Difference Between Pad Printing Ink And Silk Screen Ink
How to solve the problem of poor stability during UV ink storage?
1. UV inks are prone to cross-linking when exposed to light or heat. Therefore, direct sunlight should be avoided during use, and it cannot be stored for a long time in an environment higher than 30C. It must be stored under 16-28C in ventilation and dark.
2. Adding excessive photoinitiator in order to increase the curing speed will also affect the stability of UV ink. Therefore, excessive addition of photoinitiator should be avoided.
3. Improper mixing of UV inks produced by different manufacturers can also cause changes in the stability of UV inks. Therefore, when the ink needs to be mixed and used, it must be tested first, and can be mixed and used when there is no reaction.