UV ink because of its printing color, high gloss, water resistance, solvent resistance, abrasion resistance and curing speed, is a higher proportion of the application of label printing ink varieties, whether embossing, flexo, offset printing, are widely used. It is very important to select and use UV ink, especially to fully grasp the influencing factors, determination methods and solutions of UV ink curing, to reduce printing failures and improve label printing quality.

Application Status of UV Ink

Low-end UV ink products flooded the market

At present, there are relatively few high-end UV inks in the domestic label printing market, so people often encounter faults such as dry rollers, ink piles, flying ink, dirty plates, etc. in the printing process. UV printed label products also have problems such as poor ink adhesion, low gloss, insufficient hiding power, etc., especially the problem of low hiding power of white ink is more prominent. These are often the use of low-end UV ink caused by the failure, not only affect the printing efficiency, the quality of the label product is obviously not up to the quality requirements.

In order to avoid the possible problems of UV ink as much as possible, and to meet the quality requirements of different materials, different application fields and different printing processes, UV ink suppliers have been constantly improving and introducing new products.

UV light source has no uniform standard

The curing effect of UV ink is also directly affected by the UV light source. Since there is no uniform standard for the spectral range of UV light sources at present, the spectral range and power of commercially available UV light sources are uneven. If the UV light source and the ink matching degree is not good, it will cause the UV ink curing is not complete or the surface layer is over cured, and eventually will lead to poor ink adhesion and other quality problems.

How to choose UV ink

Ink curing performance is the most critical factor in determining the quality of UV printing products. Therefore, the selection of UV ink mainly considers whether the emission wavelength of the UV lamp used in the printing equipment of our company matches the trigger wavelength of the photoinitiator in the ink. In addition, different types of UV ink provided by different manufacturers have different key properties such as curing speed and adhesion. Generally speaking, as long as white ink and black ink can meet the requirements, other color inks will not have much problem, so black ink and white ink should be investigated.

Performance characteristics of UV light source

The wavelength range of UV light is 200 to 600nm, but ozone is generated at a wavelength of 254nm, and heat is generated at a wavelength of 400nm or more. Ozone pollutes the environment and damages the health of workers; heat not only causes the size of printed matter to be unstable, or even severely deformed, but also causes energy waste, both of which we do not want to happen in UV printing. At present, the low energy consumption UV(HUV/LEC) lamp on the market has an emission wavelength between 280 and 600nm, which avoids the ozone band, but still contains more heating bands, so LED lamps have become a new development direction of UV light sources in recent years. Single wavelength LED lamp available wavelength of 365nm, 385nm and 395nm, to avoid the ozone band and heating band, and single wavelength light source light energy is highly concentrated, ink curing efficiency is high, the use of more secure.