Advancements in UV LED Inks

V curing is a photopolymerisation process that uses UV energy to change a liquid to a solid. Upon absorption of the UV energy, the photoinitiator (Pl) produces free radicals, which initiate cross-linking with binders (monomers and oligomers) in a polymerisation reaction to cure or solidify the ink.

A photoinitiator is any chemical compound that decomposes into free radicals when exposed to light. These special additives ensure that an ink or varnish film is fully cured within a short time on exposure to light. Photoinitiators need light or high energy UV radiation, in order to trigger the polymerisation process.

Ink formulation for UV LED technology has evolved significantly and, today, there are a growing number of suppliers developing inks that work well with UV LED light sources. One of the key ingredients in the chemical formulation is a photoinitiator that reacts to the narrow wavelength spectrum UV LED energy.

Today, virtually all large ink suppliers offer products compatible with UV LED light sources.

Today, virtually all large ink suppliers offer products compatible with UV LED light sources. UV LED inks are available for digital, screen, flexo and offset printing applications. Dozens of companies offer UV LED compatible inks, coatings
and raw materials.

UV LED inks are being utilised for decorative bottle printing on glass containers for spirits, health and beauty, wine, cider, beer, bottled water, soft drinks, food and the promotional glassware industry. This decorating process utilises UV LED light sources for curing inks on glass containers to improve the quality of print.

UV LED curing has a broad usage across digital inkjet printing, adhesives and coatings. As it moves further into the more traditional printing processes of flexographic and screen printing, the UV LED ecosystem is creating low migration processes that will enable food packaging to become the next major market to realise UV LED curing benefits. The next step on the horizon is UV LED inks for low migration packaging.

Over the past few years, a growing number of ink companies have been working hand-in-hand with printing equipment 
developers to develop ink formulations that are optimised for both UV LED curing and the specific application.