UV printing is a unique method of digital printing that uses ultraviolet (UV) light to dry or cure inks, adhesives or coatings almost as soon as it touches paper, or aluminum, foam board or acrylic - in fact, the technology can be used for almost any print as long as it fits on the printer.
UV curing technology - the photochemical process of drying - was originally introduced as a way to quickly dry gel nail polish used in manicures, but it has recently been adopted by the printing industry for printing anything on signs and brochures. to beer bottles. The process is the same as traditional printing, the only difference being the inks used and the drying process - and the quality of the product produced.
In conventional printing, solvent inks are used; these can evaporate and release environmentally harmful volatile organic compounds (VOCs). The method also produces - and uses - heat and accompanying odors. In addition, it requires additional spray powder to help with the ink compensation process and drying, which can take several days. The ink is absorbed into the print media, so the colors appear to fade and discolor. The printing process is mainly limited to paper and card media and therefore cannot be used for materials such as plastic, glass, metal, aluminum foil or acrylics, such as UV printing.
In UV printing, mercury/quartz or LED lamps are used for curing rather than heating; specially designed high-intensity UV light closely follows the special ink distribution on the print media and dries once applied. Since the ink transforms almost immediately from a solid or paste to a liquid, it does not evaporate and therefore releases no VOCs, toxic fumes or ozone, making the technology environmentally sound with a virtually zero carbon footprint.
Inks, adhesives or coatings contain a mixture of liquid monomers, oligomers - polymers consisting of a small number of repeating units - and photoinitiators. During the curing process, high intensity light in the UV portion of the spectrum, at wavelengths between 200 and 400 nm, is absorbed by the photoinitiator, which undergoes a chemical reaction - chemical cross-linking - and causes the ink, coating or adhesive to harden immediately.
It's easy to see why UV printing has surpassed traditional water and solvent-based thermal drying techniques, and why it will continue to grow in popularity. Not only does the method speed up production - meaning more work in less time - as quality improves, rejection rates decrease. Wet ink droplets are eliminated, so there is no rubbing or soiling, and because it dries almost immediately, there is no evaporation and therefore no loss of coating thickness or volume. Finer detail, sharper and more vivid colors because the print media does not absorb: Choosing UV printing over traditional printing methods may be the difference between producing a luxury product and feeling less superior.
The inks also have improved physical properties, improved gloss, better scratches, chemical resistance, solvent resistance and hardness, better elasticity, and finishing products also benefit from improved strength. They are more durable, weather resistant and have greater resistance to fading, making them ideal for outdoor signage. The process is also more cost effective - more products can be printed in less time, with better quality and fewer rejects. The lack of VOCs almost means less damage to the environment, and the practice is more sustainable.