At Graph Expo, I've been stumped a couple of times by the juxtaposition of LED with UV in the discussion of curable inks. I thought LEDs were little lights that showed up on various kinds of electronics and appliances, from TVs and radios to watches. Welcome to the 21st Century! George McGill, Energy Curable Manager for Toyo Ink, explained some of the technology to me and filled me in on the types of energy savings that result from its use. First, a bit of technical detail courtesy of Wikipedia:

A light-emitting-diode (LED) is a semiconductor diode that emits light when an electric current is applied in the forward direction of the device, as in the simple LED circuit. LEDs are widely used as indicator lights on electronic devices and increasingly in higher power applications such as flashlights and area lighting. An LED is usually a small area, often with optics added to the chip to shape its radiation pattern and assist in reflection. The color of the emitted light depends on the composition and condition of the semi-conducting material used, and can be infrared, visible, or ultraviolet.

The fact that LEDs can emit UV light has caused a number of companies, both ink providers and press manufacturers, to explore this new light source. Toyo, Ryobi, and Panasonic are collaborating to bring a commercialized solution to market sometime in 2009. There are a number of green advantages of the new LED curing technology:

• Consumes about 75% less power
• Produces less heat
• Requires only one unit to cure
• The light emitters have a life expectancy of about 10,000 hours, much longer than the mercury vapor bulbs currently used for UV curing
• No heat means plastic stock doesn't distort - should be a life-saver for flexible packaging printers
• No heat means less need for air cooling around the machine
• The equipment has a smaller footprint.

Certainly this technology adds a new dimension to green printing processes. Or should we say, "sheds a new light...?"