Ultraviolet curing, popularly known as UV curing, is a photochemical process in which high-intensity ultraviolet light initiates a reaction that generates a crosslinked network of polymers that are used to instantly cure or “dry” inks, coatings or adhesives. Materials that cure using ultraviolet light provide an extremely convenient cure on-demand capability. This isn’t the case across the board. Other compounds that harden, for example, at room temperature, must be mixed and used within a certain time to obtain the best results.
How UV Curing Works
As already mentioned, UV curing involves a photochemical reaction. UV formulations usually are liquid monomers and oligomers that have been mixed with a small percent of photoinitiators, and then exposed to UV energy. Almost immediately, the formulation – inks, coatings or adhesives instantly “harden” or cure, ready for the next processing step.
Applications of UV Curing
More often than not, UV Curing is used where there is a need for converting or drying inks, adhesives or coatings. UV cured adhesive has fast become a high-speed replacement for two-part adhesives, which has eliminated the need for solvent removal, ratio mixing and potential life concern. It is used in the screen-printing process, where images on screen-printed products are polymerized using UV curing systems. These products range from T-shirts to 3D and cylindrical parts. UV curing is also used in fine instrument finishing, for example, guitars, violins, and ukuleles, among others, as well as pool cue manufacturing and in other woodcraft industries.
Printing with UV curable inks makes it possible for one to print on a very wide variety of substrates such as plastics, metal, foam boards, paper, canvas, glass, tile, films, and so many other different materials.
It doesn’t end there. There are plenty of other industries that make use of UV curings, such as medicine, automobiles, cosmetics (in the case of artificial fingernails and gel nail polish), food, science, education and art. It is also worth noting that UV curable inks have met the requirements of the publication sector on a variety of papers and boards.
Advantages of UV Curing
The main advantage of curing with ultraviolet light is the speed at which a material can be processed. UV curing is one of the fastest curing methods, which is quite an advantage over the rest. Speeding up the curing or drying step in a process can reduce errors by decreasing the time that an ink or coating spends wet. This will go on to increase the quality of a finished item and potentially allow for greater consistency. Another benefit to decreasing manufacturing time is that less space needs to be set aside for storing items which cannot be used until the drying step is finished.
In addition, since UV energy has unique interactions with different materials, UV curing provides room for the creation of products with characteristics that would be achieved through other means. This has led to UV curing becoming fundamental in many fields of manufacturing and technology, where changes in strength, hardness, durability, chemical resistance, and many other properties are required.