UV-LED Advancements Extend the Promise in Curing

When people hear the terms "light-emitting diodes" or "LEDs," most people think of visible LEDs for lighting applications. Indeed, LED technology is used increasingly throughout the world for indoor lighting, outdoor lighting, street lighting, automotive, and signage. But there are many other industrial applications such as curing (drying) and counterfeit detection. Ultraviolet (UV) LED technology for curing is one of the market segments that has gained worldwide acceptance and continues to grow. Let’s examine the state of UV curing technology and consider how well LEDs are fulfilling promises of taking over that space.

The year 2013 witnessed an expansion of LED usage in UV curing applications with higher-power emitters enabling faster cure times across a variety of life science and industrial applications.
Bill Cortelyou, President and CEO, Phoseon Technology

UV-LED curing refers to a technique that utilizes energy output from the LEDs in the UV spectrum to treat inks, coatings, adhesives, and other UV-curable materials. The energy generated by the UV light triggers a chain reaction resulting in polymerization of the material, thus hardening or curing the material.

Traditionally, mercury-based UV lamps have been utilized for curing, but now more energy-efficient and environmentally-friendly LED-based UV technology has proven a superior solution for many applications. LED curing technology uses semiconductor-based LEDs to project the UV light when an electric current is passed through them. When an LED is forward-biased, electrons are able to recombine with electron holes within the device, thus releasing energy in the form of photons.

It is an accepted fact for many industries that LED lamps provide many advantages including lower energy consumption, longer lifetime, improved robustness, smaller form factor, and faster on/off switching. Those advantages are also important in curing applications.

UV-LED curing technology has advanced significantly in the past few years and is now readily available for a variety of applications in printing, coatings, and adhesives. There are many benefits driving companies to move toward acceptance of UV-LED technology such as higher productivity and a more environmentally-friendly solution, which more and more end customers are demanding. As manufacturers are developing UV-LED curing systems, knowing how the key sub-components work together will help in creating the optimum system and thereby reducing the overall environmental impact of the process and at the same time maintaining or improving productivity and product performance.

UV-LED lamp technology has advanced to a point where it now offers enough power and capability to support a very wide range of existing and new industrial applications. With compatible material formulation, UV-LED energy output is now equivalent or better than traditional UV curing lamps. UV-LED curing units have become more efficient in delivering higher energy to the media, thus driving not only increased throughput and process flexibility but also environmentally-friendly and energy-efficient solutions. End users are rapidly moving to UV-LED curing technology due to the accumulation of benefits.